feat(ability): add Frost Shard

src/main/java/games/dmg/fantasystick/FantasyStickPlugin.java

@@ -49,6 +49,9 @@ public final class FantasyStickPlugin extends JavaPlugin {
     private games.dmg.fantasystick.ability.AbilityRegistry abilityRegistry;
     private games.dmg.fantasystick.ability.AbilityEngine abilityEngine;
     private games.dmg.fantasystick.ability.Fireball fireball;
+    private games.dmg.fantasystick.ability.FrostShard frostShard;
+    private games.dmg.fantasystick.persistence.FrostShardSettings frostShardSettings;
+    private games.dmg.fantasystick.ability.GreatSword greatSword;
     private games.dmg.fantasystick.ability.Revive revive;
     private games.dmg.fantasystick.persistence.RevivalStore revivals;
     private games.dmg.fantasystick.session.NutritionPolicy nutritionPolicy;
@@ -78,6 +81,9 @@ public final class FantasyStickPlugin extends JavaPlugin {
             var rules = progressionRules();
             var rewardRules = combatRewardRules();
             var fireballSettings = fireballSettings();
+            var greatSwordSettings = greatSwordSettings();
+            var frostShardConfiguration = frostShardConfiguration();
+            var frostShardInitial = games.dmg.fantasystick.persistence.FrostShardSettings.parse(frostShardConfiguration);
             var factory = new CharacterFactory();
             characters = new CharacterStorage(new YamlCharacterRepository(getDataFolder().toPath()), Clock.systemUTC());
             crafting = new ManualCraftingController(characters, () -> factory.create(rules),
@@ -118,11 +124,17 @@ public final class FantasyStickPlugin extends JavaPlugin {
                 notice -> notifyPlayer(generation, notice), diagnostics, presentation, adventureSettings::enabled, gameModes);
             abilityRegistry = new games.dmg.fantasystick.ability.AbilityRegistry();
             fireball = new games.dmg.fantasystick.ability.Fireball(fireballSettings);
+            frostShardSettings = new games.dmg.fantasystick.persistence.FrostShardSettings(
+                getDataFolder().toPath(), frostShardConfiguration);
+            frostShard = new games.dmg.fantasystick.ability.FrostShard(frostShardInitial);
+            greatSword = new games.dmg.fantasystick.ability.GreatSword(greatSwordSettings);
             revivals = new games.dmg.fantasystick.persistence.RevivalStore(getDataFolder().toPath());
             revive = new games.dmg.fantasystick.ability.Revive(characters, revivals, Clock.systemUTC(), nextTick,
                 (size, title) -> getServer().createInventory(null, size, title),
                 problem -> getLogger().log(Level.WARNING, "Revive transition failed", problem));
             abilityRegistry.register(fireball.definition());
+            abilityRegistry.register(frostShard.definition());
+            abilityRegistry.register(greatSword.definition());
             abilityRegistry.register(revive.definition());
             sessions.attachAbilityRegistry(abilityRegistry);
             vitals = new games.dmg.fantasystick.session.SessionVitals();
@@ -164,7 +176,8 @@ public final class FantasyStickPlugin extends JavaPlugin {
             sessionEvents.attachAbilityRegistry(abilityRegistry);
             admin = new EquipmentAdminCommand(receipts, sessions, getServer(), nextTick,
                 problem -> getLogger().log(Level.WARNING, "Equipment admin " + problem.operation()
-                    + " for player " + problem.player(), problem.cause()), adventureSettings);
+                    + " for player " + problem.player(), problem.cause()), adventureSettings,
+                frostShardSettings, frostShard, abilityRegistry);
             var command = java.util.Objects.requireNonNull(getCommand("fantasystick"), "Missing packaged fantasystick command");
             command.setExecutor(admin);
             command.setTabCompleter(admin);
@@ -179,6 +192,8 @@ public final class FantasyStickPlugin extends JavaPlugin {
             getServer().getPluginManager().registerEvents(combatExperience, this);
             combatExperience.install(this);
             getServer().getPluginManager().registerEvents(fireball, this);
+            getServer().getPluginManager().registerEvents(frostShard, this);
+            getServer().getPluginManager().registerEvents(greatSword, this);
             getServer().getPluginManager().registerEvents(revive, this);
             getServer().getPluginManager().registerEvents(localBasicAttack, this);
             getServer().getPluginManager().registerEvents(nutritionPolicy, this);
@@ -223,6 +238,9 @@ public final class FantasyStickPlugin extends JavaPlugin {
         var closingCombatExperience = combatExperience; combatExperience = null;
         var closingAbilityEngine = abilityEngine; abilityEngine = null;
         var closingFireball = fireball; fireball = null;
+        var closingFrostShard = frostShard; frostShard = null;
+        var closingFrostSettings = frostShardSettings; frostShardSettings = null;
+        var closingGreatSword = greatSword; greatSword = null;
         var closingRevive = revive; revive = null;
         var closingRevivals = revivals; revivals = null;
         abilityRegistry = null;
@@ -231,14 +249,19 @@ public final class FantasyStickPlugin extends JavaPlugin {
         if (closingPresentation != null) cleanup("presentation", closingPresentation::close);
         if (closingProtocol != null) cleanup("protocol presentation", closingProtocol::close);
         if (closingAdmin != null) cleanup("admin command", closingAdmin::close);
-        if (closingSettings != null) {
-            configurationDrain = closingSettings.drained();
-            cleanup("configuration", closingSettings::close);
-        }
+        if (closingSettings != null) cleanup("configuration", closingSettings::close);
+        if (closingFrostSettings != null) cleanup("Frost Shard configuration", closingFrostSettings::close);
+        configurationDrain = java.util.concurrent.CompletableFuture.allOf(
+            closingSettings == null ? java.util.concurrent.CompletableFuture.completedFuture(null)
+                : closingSettings.drained().toCompletableFuture(),
+            closingFrostSettings == null ? java.util.concurrent.CompletableFuture.completedFuture(null)
+                : closingFrostSettings.drained().toCompletableFuture());
         if (closingBooks != null) cleanup("character book", closingBooks::close);
         if (closingBasicAttack != null) cleanup("basic attack", closingBasicAttack::close);
         if (closingCombatExperience != null) cleanup("combat experience", closingCombatExperience::close);
         if (closingFireball != null) cleanup("Fireball", closingFireball::close);
+        if (closingFrostShard != null) cleanup("Frost Shard", closingFrostShard::close);
+        if (closingGreatSword != null) cleanup("Great Sword", closingGreatSword::close);
         if (closingRevive != null) cleanup("Revive", closingRevive::close);
         if (closingAbilityEngine != null) cleanup("ability engine", closingAbilityEngine::close);
         if (closingNutrition != null) cleanup("nutrition policy", closingNutrition::close);
@@ -255,6 +278,8 @@ public final class FantasyStickPlugin extends JavaPlugin {
         unregister(closingPartyCombat);
         unregister(closingCombatExperience);
         unregister(closingFireball);
+        unregister(closingFrostShard);
+        unregister(closingGreatSword);
         unregister(closingRevive);
         unregister(closingBasicAttack);
         unregister(closingNutrition);
@@ -326,6 +351,27 @@ public final class FantasyStickPlugin extends JavaPlugin {
         }
     }
 
+    private java.util.Map<String, String> frostShardConfiguration() {
+        var values = new java.util.LinkedHashMap<String, String>();
+        for (String key : games.dmg.fantasystick.persistence.FrostShardSettings.keys()) {
+            values.put(key, getConfig().getString(key,
+                games.dmg.fantasystick.persistence.FrostShardSettings.defaultValue(key)));
+        }
+        games.dmg.fantasystick.persistence.FrostShardSettings.parse(values);
+        return java.util.Map.copyOf(values);
+    }
+
+    private games.dmg.fantasystick.ability.GreatSword.Settings greatSwordSettings() {
+        try {
+            var base = new java.math.BigInteger(getConfig().getString("great-sword-base-damage", "7"));
+            var seconds = new java.math.BigDecimal(getConfig().getString("great-sword-recovery-seconds", "1.2"));
+            var recovery = java.time.Duration.ofNanos(seconds.movePointRight(9).toBigIntegerExact().longValueExact());
+            return new games.dmg.fantasystick.ability.GreatSword.Settings(base, recovery);
+        } catch (ArithmeticException | NumberFormatException invalid) {
+            throw new IllegalArgumentException("Great Sword settings must use supported nonnegative numeric values", invalid);
+        }
+    }
+
     private java.time.Duration switchDelay() {
         Object configured = getConfig().get("character-swap-cooldown-seconds", 900);
         String value = String.valueOf(configured);

src/main/java/games/dmg/fantasystick/ability/AbilityRegistry.java

@@ -17,6 +17,15 @@ public final class AbilityRegistry {
         }
     }
 
+    /** Replace one registered definition after an acknowledged runtime configuration save. */
+    public void replace(AbilityDefinition definition) {
+        Objects.requireNonNull(definition);
+        definitions.compute(definition.id(), (id, existing) -> {
+            if (existing == null) throw new IllegalArgumentException("Unknown ability ID: " + id);
+            return definition;
+        });
+    }
+
     public Optional<AbilityDefinition> find(String id) {
         return id == null ? Optional.empty() : Optional.ofNullable(definitions.get(id));
     }

src/main/java/games/dmg/fantasystick/ability/FrostShard.java

@@ -0,0 +1,233 @@
+package games.dmg.fantasystick.ability;
+
+import games.dmg.fantasystick.progression.Stat;
+import games.dmg.fantasystick.session.ControlInput;
+import java.math.BigDecimal;
+import java.math.BigInteger;
+import java.time.Duration;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Objects;
+import java.util.UUID;
+import org.bukkit.Location;
+import org.bukkit.Material;
+import org.bukkit.Particle;
+import org.bukkit.damage.DamageSource;
+import org.bukkit.damage.DamageType;
+import org.bukkit.entity.LivingEntity;
+import org.bukkit.entity.Snowball;
+import org.bukkit.event.EventHandler;
+import org.bukkit.event.EventPriority;
+import org.bukkit.event.Listener;
+import org.bukkit.event.entity.EntityDamageEvent;
+import org.bukkit.event.entity.ProjectileHitEvent;
+import org.bukkit.potion.PotionEffect;
+import org.bukkit.potion.PotionEffectType;
+import org.bukkit.util.Vector;
+
+/** Frost Shard's bounded direct projectile damage and owned Slowness adapter. */
+public final class FrostShard implements AbilityEffect, Listener, AutoCloseable {
+    public record Settings(BigInteger baseDamage, Duration cooldown, double range, Duration lifetime,
+                           double speedPerTick, int slownessAmplifier, Duration slownessDuration) {
+        public Settings {
+            Objects.requireNonNull(baseDamage); Objects.requireNonNull(cooldown); Objects.requireNonNull(lifetime);
+            Objects.requireNonNull(slownessDuration);
+            if (baseDamage.signum() < 0 || cooldown.isNegative() || cooldown.compareTo(Duration.ofDays(365)) > 0
+                    || !Double.isFinite(range) || range <= 0 || range > 1024
+                    || lifetime.isZero() || lifetime.isNegative() || lifetime.compareTo(Duration.ofSeconds(60)) > 0
+                    || !Double.isFinite(speedPerTick) || speedPerTick < 0.01 || speedPerTick > 64
+                    || slownessAmplifier < 0 || slownessAmplifier > 255
+                    || slownessDuration.isZero() || slownessDuration.isNegative()
+                    || slownessDuration.compareTo(Duration.ofDays(1)) > 0) {
+                throw new IllegalArgumentException("Invalid Frost Shard settings");
+            }
+        }
+        public static Settings defaults() {
+            return new Settings(BigInteger.valueOf(4), Duration.ofSeconds(5), 32, Duration.ofSeconds(5),
+                1, 0, Duration.ofSeconds(2));
+        }
+    }
+
+    private final class State implements AutoCloseable {
+        final Snowball projectile;
+        final AbilityExecution execution;
+        final Location origin;
+        final BigInteger intelligence;
+        final Settings settings;
+        LivingEntity target;
+        boolean accepted;
+        boolean finished;
+        State(Snowball projectile, AbilityExecution execution, Location origin, BigInteger intelligence, Settings settings) {
+            this.projectile = projectile; this.execution = execution; this.origin = origin;
+            this.intelligence = intelligence; this.settings = settings;
+        }
+        @Override public void close() {
+            if (finished) return;
+            finished = true; projectiles.remove(projectile.getUniqueId(), this); projectile.remove();
+        }
+    }
+
+    private static final class SlowLease implements AutoCloseable {
+        private final LivingEntity target;
+        private final PotionEffect previous;
+        private final PotionEffect applied;
+        private final long started = System.nanoTime();
+        private boolean owned;
+        private boolean closed;
+        SlowLease(LivingEntity target, PotionEffect applied) {
+            this.target = target; this.previous = target.getPotionEffect(PotionEffectType.SLOWNESS); this.applied = applied;
+        }
+        boolean apply() { owned = target.addPotionEffect(applied); return owned; }
+        @Override public void close() {
+            if (closed) return;
+            closed = true;
+            if (!owned) return;
+            var current = target.getPotionEffect(PotionEffectType.SLOWNESS);
+            long elapsed = Math.max(0, (System.nanoTime() - started) / 50_000_000L);
+            int expected = (int) Math.max(0, (long) applied.getDuration() - elapsed);
+            if (current == null || current.getAmplifier() != applied.getAmplifier()
+                    || current.getDuration() > expected + 2) return;
+            target.removePotionEffect(PotionEffectType.SLOWNESS);
+            if (previous != null) {
+                int remaining = (int) Math.max(0, (long) previous.getDuration() - elapsed);
+                if (remaining > 0) target.addPotionEffect(previous.withDuration(remaining));
+            }
+        }
+    }
+
+    private volatile Settings settings;
+    private final Map<UUID, State> projectiles = new HashMap<>();
+    private State damaging;
+    private boolean closed;
+
+    public FrostShard(Settings settings) { this.settings = Objects.requireNonNull(settings); }
+
+    public void configure(Settings settings) { this.settings = Objects.requireNonNull(settings); }
+
+    public AbilityDefinition definition() {
+        var current = settings;
+        return new AbilityDefinition("frost_shard", "Frost Shard", Material.PRISMARINE_SHARD,
+            List.of("Launch a bounded frost projectile.",
+                "Deals " + current.baseDamage() + " + INT modifier damage and Slowness "
+                    + level(current.slownessAmplifier()) + " for " + seconds(current.slownessDuration()) + "s."),
+            "Use the equipped shard; a miss still spends the cooldown.",
+            Map.of(Stat.INT, BigInteger.valueOf(12), Stat.WIS, BigInteger.TEN), BigInteger.ONE,
+            AbilityDefinition.Activation.PROJECTILE, ControlInput.Gesture.USE, current.cooldown(),
+            Map.of("base-damage", new BigDecimal(current.baseDamage()),
+                "range", BigDecimal.valueOf(current.range()).stripTrailingZeros(),
+                "lifetime", seconds(current.lifetime()), "projectile-speed", BigDecimal.valueOf(current.speedPerTick()),
+                "slowness-amplifier", BigDecimal.valueOf(current.slownessAmplifier()),
+                "slowness-duration", seconds(current.slownessDuration())),
+            AbilityDefinition.TargetPolicy.PROJECTILE_HOSTILE, this);
+    }
+
+    public static BigInteger damage(BigInteger intelligence) {
+        return damage(BigInteger.valueOf(4), intelligence);
+    }
+
+    static BigInteger damage(BigInteger base, BigInteger intelligence) {
+        Objects.requireNonNull(base); Objects.requireNonNull(intelligence);
+        if (base.signum() < 0 || intelligence.signum() < 0) throw new IllegalArgumentException("Invalid Frost Shard damage input");
+        BigInteger delta = intelligence.subtract(BigInteger.TEN);
+        BigInteger[] divided = delta.divideAndRemainder(BigInteger.TWO);
+        BigInteger modifier = divided[0];
+        if (delta.signum() < 0 && divided[1].signum() != 0) modifier = modifier.subtract(BigInteger.ONE);
+        return base.add(modifier);
+    }
+
+    @Override public void activate(AbilityExecution execution) {
+        if (closed || !execution.stillCurrent()) return;
+        var current = settings;
+        var player = execution.input().player();
+        Location origin = player.getEyeLocation().clone();
+        Vector direction = origin.getDirection();
+        if (!Double.isFinite(direction.getX()) || !Double.isFinite(direction.getY()) || !Double.isFinite(direction.getZ())
+                || direction.lengthSquared() == 0) throw new IllegalStateException("Frost Shard direction is unavailable");
+        var projectile = player.launchProjectile(Snowball.class, direction.normalize().multiply(current.speedPerTick()));
+        var state = new State(projectile, execution, origin, execution.character().stats().get(Stat.INT), current);
+        if (projectiles.putIfAbsent(projectile.getUniqueId(), state) != null) {
+            projectile.remove(); throw new IllegalStateException("Duplicate Frost Shard projectile identity");
+        }
+        execution.own(state);
+        long rangeTicks = Math.max(1, (long) Math.ceil(current.range() / current.speedPerTick()));
+        execution.later(Duration.ofMillis(Math.multiplyExact(rangeTicks, 50)), () -> {
+            if (projectiles.containsKey(projectile.getUniqueId())) execution.finish();
+        });
+        execution.later(current.lifetime(), () -> {
+            if (projectiles.containsKey(projectile.getUniqueId())) execution.finish();
+        });
+        player.getWorld().spawnParticle(Particle.SNOWFLAKE, origin, 8, 0.15, 0.15, 0.15, 0.01);
+    }
+
+    @EventHandler(priority = EventPriority.MONITOR)
+    public void hit(ProjectileHitEvent event) {
+        var state = projectiles.remove(event.getEntity().getUniqueId());
+        if (state == null) return;
+        boolean retainExecution = false;
+        try {
+            if (closed || event.isCancelled() || !state.execution.stillCurrent()
+                    || !(event.getHitEntity() instanceof LivingEntity target) || !inRange(state, event.getEntity().getLocation())
+                    || state.execution.eligible(List.of(target), 1).isEmpty()) return;
+            var current = state.settings;
+            BigInteger amount = damage(current.baseDamage(), state.intelligence);
+            double nativeDamage = amount.bitLength() > 1023 ? Double.MAX_VALUE : amount.doubleValue();
+            var source = DamageSource.builder(DamageType.FREEZE).withCausingEntity(state.execution.input().player())
+                .withDirectEntity(state.projectile).withDamageLocation(state.projectile.getLocation()).build();
+            state.target = target; damaging = state;
+            try { target.damage(nativeDamage, source); }
+            finally { if (damaging == state) damaging = null; }
+            if (state.accepted && state.execution.stillCurrent()) {
+                int ticks = Math.toIntExact(Math.max(1,
+                    (current.slownessDuration().toNanos() + 49_999_999L) / 50_000_000L));
+                var lease = new SlowLease(target, new PotionEffect(PotionEffectType.SLOWNESS, ticks,
+                    current.slownessAmplifier(), false, true, true));
+                if (lease.apply()) {
+                    state.execution.own(lease);
+                    state.execution.later(current.slownessDuration(), state.execution::finish);
+                    retainExecution = true;
+                }
+            }
+        } finally {
+            state.close();
+            if (!retainExecution) state.execution.finish();
+        }
+    }
+
+    private boolean inRange(State state, Location current) {
+        return current.getWorld() != null && state.origin.getWorld() != null
+            && current.getWorld().equals(state.origin.getWorld())
+            && current.distanceSquared(state.origin) <= state.settings.range() * state.settings.range();
+    }
+
+    @EventHandler(priority = EventPriority.MONITOR, ignoreCancelled = true)
+    public void acceptedDamage(EntityDamageEvent event) {
+        var state = damaging;
+        if (state == null || state.accepted || event.getEntity() != state.target || event.getFinalDamage() <= 0
+                || !Double.isFinite(event.getFinalDamage())) return;
+        var direct = event.getDamageSource().getDirectEntity();
+        if (direct != state.projectile && (!(event instanceof org.bukkit.event.entity.EntityDamageByEntityEvent byEntity)
+                || byEntity.getDamager() != state.projectile)) return;
+        state.accepted = true;
+        state.execution.report(AbilityReport.Type.DAMAGE, event.getEntity(), BigDecimal.valueOf(event.getFinalDamage()));
+    }
+
+    private static String level(int amplifier) {
+        return switch (amplifier + 1) {
+            case 1 -> "I"; case 2 -> "II"; case 3 -> "III"; case 4 -> "IV"; case 5 -> "V";
+            default -> Integer.toString(amplifier + 1);
+        };
+    }
+
+    private static BigDecimal seconds(Duration duration) {
+        return BigDecimal.valueOf(duration.getSeconds()).add(BigDecimal.valueOf(duration.getNano(), 9))
+            .stripTrailingZeros();
+    }
+
+    @Override public void close() {
+        if (closed) return;
+        closed = true;
+        for (var state : List.copyOf(projectiles.values())) state.execution.finish();
+        projectiles.clear(); damaging = null;
+    }
+}

src/main/java/games/dmg/fantasystick/ability/GreatSword.java

@@ -0,0 +1,116 @@
+package games.dmg.fantasystick.ability;
+
+import games.dmg.fantasystick.progression.Stat;
+import games.dmg.fantasystick.session.ControlInput;
+import java.math.BigDecimal;
+import java.math.BigInteger;
+import java.time.Duration;
+import java.util.List;
+import java.util.Map;
+import java.util.Objects;
+import org.bukkit.Material;
+import org.bukkit.damage.DamageSource;
+import org.bukkit.damage.DamageType;
+import org.bukkit.entity.LivingEntity;
+import org.bukkit.event.EventHandler;
+import org.bukkit.event.EventPriority;
+import org.bukkit.event.Listener;
+import org.bukkit.event.entity.EntityDamageByEntityEvent;
+
+/** Great Sword's charge-scaled direct melee damage, replacing the contained native weapon hit. */
+public final class GreatSword implements AbilityEffect, Listener, AutoCloseable {
+    public record Settings(BigInteger baseDamage, Duration recovery) {
+        public Settings {
+            Objects.requireNonNull(baseDamage); Objects.requireNonNull(recovery);
+            if (baseDamage.signum() < 0 || recovery.isNegative()
+                    || recovery.compareTo(Duration.ofDays(365)) > 0) {
+                throw new IllegalArgumentException("Invalid Great Sword settings");
+            }
+        }
+        public static Settings defaults() { return new Settings(BigInteger.valueOf(7), Duration.ofMillis(1200)); }
+    }
+
+    private static final class Attempt {
+        final AbilityExecution execution;
+        final LivingEntity target;
+        boolean reported;
+        Attempt(AbilityExecution execution, LivingEntity target) {
+            this.execution = execution; this.target = target;
+        }
+    }
+
+    private final Settings settings;
+    private Attempt damaging;
+    private boolean closed;
+
+    public GreatSword(Settings settings) { this.settings = Objects.requireNonNull(settings); }
+
+    public AbilityDefinition definition() {
+        return new AbilityDefinition("great_sword", "Great Sword", Material.WOODEN_SWORD,
+            List.of("Charge a contained melee strike.",
+                "Fully charged: " + settings.baseDamage() + " + STR modifier damage."),
+            "Attack with the equipped sword; partial charge follows the native attack curve.",
+            Map.of(Stat.STR, BigInteger.valueOf(12)), BigInteger.ONE,
+            AbilityDefinition.Activation.IMMEDIATE, ControlInput.Gesture.ATTACK, settings.recovery(),
+            Map.of("base-damage", new BigDecimal(settings.baseDamage())),
+            AbilityDefinition.TargetPolicy.HOSTILE, this);
+    }
+
+    public static BigDecimal damage(BigInteger strength, float charge) {
+        return damage(BigInteger.valueOf(7), strength, charge);
+    }
+
+    static BigDecimal damage(BigInteger base, BigInteger strength, float charge) {
+        Objects.requireNonNull(base); Objects.requireNonNull(strength);
+        if (base.signum() < 0 || strength.signum() < 0 || !Float.isFinite(charge) || charge < 0 || charge > 1) {
+            throw new IllegalArgumentException("Invalid Great Sword damage input");
+        }
+        BigInteger delta = strength.subtract(BigInteger.TEN);
+        BigInteger[] divided = delta.divideAndRemainder(BigInteger.TWO);
+        BigInteger modifier = divided[0];
+        if (delta.signum() < 0 && divided[1].signum() != 0) modifier = modifier.subtract(BigInteger.ONE);
+        BigDecimal full = new BigDecimal(base.add(modifier));
+        BigDecimal nativeCharge = new BigDecimal(Float.toString(charge));
+        BigDecimal curve = new BigDecimal("0.2").add(new BigDecimal("0.8").multiply(nativeCharge.multiply(nativeCharge)));
+        return full.multiply(curve).stripTrailingZeros();
+    }
+
+    @Override public boolean accepts(ControlInput input) {
+        return !closed && input.target() instanceof LivingEntity;
+    }
+
+    @Override public void activate(AbilityExecution execution) {
+        if (closed || !execution.stillCurrent() || !(execution.input().target() instanceof LivingEntity target)) return;
+        BigDecimal amount = damage(settings.baseDamage(), execution.character().stats().get(Stat.STR),
+            execution.input().attackStrength());
+        double nativeDamage = amount.compareTo(BigDecimal.valueOf(Double.MAX_VALUE)) > 0
+            ? Double.MAX_VALUE : amount.doubleValue();
+        if (!Double.isFinite(nativeDamage) || nativeDamage <= 0) {
+            throw new IllegalStateException("Great Sword damage is outside the native finite range");
+        }
+        var player = execution.input().player();
+        var source = DamageSource.builder(DamageType.PLAYER_ATTACK).withCausingEntity(player)
+            .withDirectEntity(player).build();
+        var attempt = new Attempt(execution, target);
+        damaging = attempt;
+        try { target.damage(nativeDamage, source); }
+        finally { if (damaging == attempt) damaging = null; }
+    }
+
+    @EventHandler(priority = EventPriority.MONITOR, ignoreCancelled = true)
+    public void acceptedDamage(EntityDamageByEntityEvent event) {
+        var attempt = damaging;
+        if (closed || attempt == null || attempt.reported || event.isCancelled()
+                || event.getDamager() != attempt.execution.input().player() || event.getEntity() != attempt.target
+                || (event.getDamageSource().getCausingEntity() != null
+                    && event.getDamageSource().getCausingEntity() != attempt.execution.input().player())
+                || (event.getDamageSource().getDirectEntity() != null
+                    && event.getDamageSource().getDirectEntity() != attempt.execution.input().player())
+                || event.getFinalDamage() <= 0 || !Double.isFinite(event.getFinalDamage())) return;
+        attempt.reported = true;
+        attempt.execution.report(AbilityReport.Type.DAMAGE, event.getEntity(),
+            BigDecimal.valueOf(event.getFinalDamage()).stripTrailingZeros());
+    }
+
+    @Override public void close() { closed = true; damaging = null; }
+}

src/main/java/games/dmg/fantasystick/book/CharacterBookController.java

@@ -174,7 +174,7 @@ public final class CharacterBookController implements Consumer<ControlInput>, Au
         String text = definition.name() + "\nIcon: " + definition.icon().name()
             + "\n\n" + String.join("\n", definition.lore()) + "\n\n" + definition.instructions()
             + "\nRequires: " + requirements + "\nCost: " + definition.pointCost()
-            + "\nCooldown: " + definition.cooldown().toSeconds() + "s" + parameters + "\n\n" + state;
+            + "\nCooldown: " + durationSeconds(definition.cooldown()) + "s" + parameters + "\n\n" + state;
         var pages = new java.util.ArrayList<>(BookPagination.pages(text));
         if (!learned && stats && record.unspentPoints().compareTo(definition.pointCost()) >= 0) {
             pages.add(Component.text("Ability action\n\n").append(abilityButton("Learn", ABILITY_UNLOCK, view, definition.id(), null)));
@@ -191,6 +191,11 @@ public final class CharacterBookController implements Consumer<ControlInput>, Au
         return java.util.List.copyOf(pages);
     }
 
+    private static String durationSeconds(java.time.Duration duration) {
+        return java.math.BigDecimal.valueOf(duration.getSeconds())
+            .add(java.math.BigDecimal.valueOf(duration.getNano(), 9)).stripTrailingZeros().toPlainString();
+    }
+
     private static Component abilityButton(String label, net.kyori.adventure.key.Key action, AbilityView view,
                                            String ability, Integer slot) {
         String payload = "\"" + view.nonce() + ":" + ability + (slot == null ? "" : ":" + slot) + "\"";

src/main/java/games/dmg/fantasystick/persistence/FrostShardSettings.java

@@ -0,0 +1,198 @@
+package games.dmg.fantasystick.persistence;
+
+import games.dmg.fantasystick.ability.FrostShard;
+import java.io.IOException;
+import java.nio.ByteBuffer;
+import java.nio.channels.FileChannel;
+import java.nio.channels.OverlappingFileLockException;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.LinkOption;
+import java.nio.file.Path;
+import java.nio.file.StandardCopyOption;
+import java.nio.file.StandardOpenOption;
+import java.time.Duration;
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Objects;
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.CompletionStage;
+import java.util.concurrent.Executors;
+import java.util.concurrent.RejectedExecutionException;
+import org.yaml.snakeyaml.LoaderOptions;
+import org.yaml.snakeyaml.Yaml;
+import org.yaml.snakeyaml.constructor.SafeConstructor;
+
+/** Serialized durable Frost Shard settings; publication remains a server-thread caller decision. */
+public final class FrostShardSettings implements AutoCloseable {
+    private static final int MAX_BYTES = 1_048_576;
+    public static final String BASE_DAMAGE = "frost-shard-base-damage";
+    public static final String COOLDOWN = "frost-shard-cooldown-seconds";
+    public static final String RANGE = "frost-shard-range-blocks";
+    public static final String LIFETIME = "frost-shard-lifetime-seconds";
+    public static final String SPEED = "frost-shard-projectile-speed-blocks-per-tick";
+    public static final String AMPLIFIER = "frost-shard-slowness-amplifier";
+    public static final String SLOWNESS = "frost-shard-slowness-duration-seconds";
+    private static final List<String> KEYS = List.of(BASE_DAMAGE, COOLDOWN, LIFETIME, SPEED, RANGE, AMPLIFIER, SLOWNESS);
+    private static final Map<String, String> DEFAULTS = Map.of(BASE_DAMAGE, "4", COOLDOWN, "5", RANGE, "32",
+        LIFETIME, "5", SPEED, "1", AMPLIFIER, "0", SLOWNESS, "2");
+
+    @FunctionalInterface interface Replacement { void move(Path from, Path to) throws IOException; }
+    public record Update(String key, String value, FrostShard.Settings settings,
+                         Map<String, String> values, long sequence) {
+        public Update { values = Map.copyOf(values); }
+    }
+
+    private final Path directory;
+    private final Replacement replacement;
+    private final java.util.concurrent.ExecutorService worker = Executors.newSingleThreadExecutor(
+        task -> new Thread(task, "fantasy-frost-shard-configuration"));
+    private volatile Map<String, String> effectiveValues;
+    private Map<String, String> persistedValues;
+    private long persistedSequence;
+    private long publishedSequence;
+    private boolean closed;
+    private int pending;
+    private final CompletableFuture<Void> drained = new CompletableFuture<>();
+
+    public FrostShardSettings(Path directory, Map<String, String> initial) {
+        this(directory, initial, (from, to) -> Files.move(from, to,
+            StandardCopyOption.ATOMIC_MOVE, StandardCopyOption.REPLACE_EXISTING));
+    }
+
+    FrostShardSettings(Path directory, Map<String, String> initial, Replacement replacement) {
+        this.directory = Objects.requireNonNull(directory).toAbsolutePath();
+        this.replacement = Objects.requireNonNull(replacement);
+        var copy = new LinkedHashMap<String, String>();
+        for (String key : KEYS) copy.put(key, Objects.requireNonNull(initial.get(key)));
+        parse(copy);
+        effectiveValues = Map.copyOf(copy); persistedValues = Map.copyOf(copy);
+    }
+
+    public static List<String> keys() { return KEYS; }
+    public static String defaultValue(String key) { return DEFAULTS.get(key); }
+    public String value(String key) { return effectiveValues.get(key); }
+    public FrostShard.Settings settings() { return parse(effectiveValues); }
+
+    /** Publish only after the caller returns the durable acknowledgment to the server thread. */
+    public synchronized void publish(Update update) {
+        Objects.requireNonNull(update);
+        if (update.sequence() <= publishedSequence) return;
+        parse(update.values());
+        effectiveValues = update.values(); publishedSequence = update.sequence();
+    }
+
+    public CompletionStage<Update> set(String key, String value) {
+        Objects.requireNonNull(key); Objects.requireNonNull(value);
+        if (!KEYS.contains(key)) return CompletableFuture.failedStage(new IllegalArgumentException("Unknown setting"));
+        String accepted = canonical(key, value);
+        var preview = new LinkedHashMap<>(effectiveValues); preview.put(key, accepted);
+        parse(preview); // Fail malformed/out-of-range command input before queueing accepted persistence.
+        synchronized (this) {
+            if (closed) return CompletableFuture.failedStage(new IOException("Configuration store is closed"));
+            pending++;
+        }
+        try {
+            return CompletableFuture.supplyAsync(() -> {
+                try {
+                    var next = new LinkedHashMap<>(persistedValues);
+                    next.put(key, accepted);
+                    var parsed = parse(next);
+                    save(key, accepted);
+                    persistedValues = Map.copyOf(next);
+                    return new Update(key, accepted, parsed, persistedValues, ++persistedSequence);
+                } catch (IOException | RuntimeException failure) {
+                    throw new java.util.concurrent.CompletionException(failure instanceof IllegalArgumentException
+                        ? failure : new IOException("Frost Shard configuration save refused or failed; effective settings unchanged"));
+                } finally { finished(); }
+            }, worker).minimalCompletionStage();
+        } catch (RejectedExecutionException rejected) {
+            finished();
+            return CompletableFuture.failedStage(new IOException("Configuration store is closed"));
+        }
+    }
+
+    private static String canonical(String key, String raw) {
+        try {
+            if (key.equals(BASE_DAMAGE) || key.equals(AMPLIFIER)) return new java.math.BigInteger(raw).toString();
+            return new java.math.BigDecimal(raw).stripTrailingZeros().toPlainString();
+        } catch (NumberFormatException invalid) { throw new IllegalArgumentException("Invalid value", invalid); }
+    }
+
+    public static FrostShard.Settings parse(Map<String, String> values) {
+        try {
+            var base = new java.math.BigInteger(values.get(BASE_DAMAGE));
+            var cooldown = seconds(values.get(COOLDOWN));
+            double range = finite(values.get(RANGE));
+            var lifetime = seconds(values.get(LIFETIME));
+            double speed = finite(values.get(SPEED));
+            int amplifier = new java.math.BigInteger(values.get(AMPLIFIER)).intValueExact();
+            var slowness = seconds(values.get(SLOWNESS));
+            return new FrostShard.Settings(base, cooldown, range, lifetime, speed, amplifier, slowness);
+        } catch (ArithmeticException | NumberFormatException | NullPointerException invalid) {
+            throw new IllegalArgumentException("Frost Shard settings must use supported numeric values", invalid);
+        }
+    }
+
+    private static Duration seconds(String value) {
+        var nanos = new java.math.BigDecimal(value).movePointRight(9).toBigIntegerExact().longValueExact();
+        return Duration.ofNanos(nanos);
+    }
+
+    private static double finite(String value) {
+        double result = new java.math.BigDecimal(value).doubleValue();
+        if (!Double.isFinite(result)) throw new IllegalArgumentException("Setting is not finite");
+        return result;
+    }
+
+    private void save(String key, String value) throws IOException {
+        Files.createDirectories(directory);
+        if (!Files.isDirectory(directory, LinkOption.NOFOLLOW_LINKS)) throw new IOException("Unsafe directory");
+        var file = directory.resolve("config.yml");
+        var lockFile = directory.resolve(".config.lock");
+        if (Files.exists(lockFile, LinkOption.NOFOLLOW_LINKS)
+                && !Files.isRegularFile(lockFile, LinkOption.NOFOLLOW_LINKS)) throw new IOException("Unsafe lock");
+        try (var channel = FileChannel.open(lockFile, StandardOpenOption.CREATE, StandardOpenOption.WRITE,
+                LinkOption.NOFOLLOW_LINKS); var lock = channel.tryLock()) {
+            if (lock == null) throw new IOException("Configuration busy");
+            var options = new LoaderOptions(); options.setAllowDuplicateKeys(false);
+            options.setMaxAliasesForCollections(20); options.setCodePointLimit(MAX_BYTES);
+            var yaml = new Yaml(new SafeConstructor(options));
+            Map<String, Object> document = new LinkedHashMap<>();
+            if (Files.exists(file, LinkOption.NOFOLLOW_LINKS)) {
+                if (!Files.isRegularFile(file, LinkOption.NOFOLLOW_LINKS)) throw new IOException("Unsafe configuration");
+                byte[] bytes;
+                try (var input = Files.newInputStream(file, LinkOption.NOFOLLOW_LINKS)) { bytes = input.readNBytes(MAX_BYTES + 1); }
+                if (bytes.length > MAX_BYTES) throw new IOException("Configuration too large");
+                Object loaded = yaml.load(StandardCharsets.UTF_8.newDecoder().decode(ByteBuffer.wrap(bytes)).toString());
+                if (loaded != null) {
+                    if (!(loaded instanceof Map<?, ?> map)) throw new IOException("Invalid configuration root");
+                    for (var entry : map.entrySet()) {
+                        if (!(entry.getKey() instanceof String savedKey)) throw new IOException("Invalid configuration key");
+                        document.put(savedKey, entry.getValue());
+                    }
+                }
+            }
+            document.put(key, value);
+            byte[] bytes = yaml.dump(document).getBytes(StandardCharsets.UTF_8);
+            if (bytes.length > MAX_BYTES) throw new IOException("Configuration too large");
+            Path temporary = Files.createTempFile(directory, ".config-", ".tmp");
+            try {
+                try (var output = FileChannel.open(temporary, StandardOpenOption.WRITE, LinkOption.NOFOLLOW_LINKS)) {
+                    var buffer = ByteBuffer.wrap(bytes); while (buffer.hasRemaining()) output.write(buffer); output.force(true);
+                }
+                replacement.move(temporary, file);
+            } finally { Files.deleteIfExists(temporary); }
+        } catch (OverlappingFileLockException busy) { throw new IOException("Configuration busy"); }
+    }
+
+    private synchronized void finished() {
+        pending--;
+        if (closed && pending == 0) drained.complete(null);
+    }
+    public CompletionStage<Void> drained() { return drained.minimalCompletionStage(); }
+    @Override public synchronized void close() {
+        closed = true; worker.shutdown(); if (pending == 0) drained.complete(null);
+    }
+}

src/main/java/games/dmg/fantasystick/session/EquipmentAdminCommand.java

@@ -21,6 +21,9 @@ public final class EquipmentAdminCommand implements TabExecutor, AutoCloseable {
     private final Consumer<Failure> diagnostics;
     private volatile boolean closed;
     private games.dmg.fantasystick.persistence.AdventureSettings settings;
+    private games.dmg.fantasystick.persistence.FrostShardSettings frostSettings;
+    private games.dmg.fantasystick.ability.FrostShard frostShard;
+    private games.dmg.fantasystick.ability.AbilityRegistry abilities;
 
     public EquipmentAdminCommand(EquipmentSessionStore receipts, EquipmentSessions sessions, Server server,
                                  Consumer<Runnable> nextTick, Consumer<Failure> diagnostics) {
@@ -38,6 +41,18 @@ public final class EquipmentAdminCommand implements TabExecutor, AutoCloseable {
         this.settings = Objects.requireNonNull(settings);
     }
 
+    public EquipmentAdminCommand(EquipmentSessionStore receipts, EquipmentSessions sessions, Server server,
+                                 Consumer<Runnable> nextTick, Consumer<Failure> diagnostics,
+                                 games.dmg.fantasystick.persistence.AdventureSettings settings,
+                                 games.dmg.fantasystick.persistence.FrostShardSettings frostSettings,
+                                 games.dmg.fantasystick.ability.FrostShard frostShard,
+                                 games.dmg.fantasystick.ability.AbilityRegistry abilities) {
+        this(receipts, sessions, server, nextTick, diagnostics, settings);
+        this.frostSettings = Objects.requireNonNull(frostSettings);
+        this.frostShard = Objects.requireNonNull(frostShard);
+        this.abilities = Objects.requireNonNull(abilities);
+    }
+
     @Override public boolean onCommand(CommandSender sender, Command command, String label, String[] args) {
         if (closed) return true;
         if (!sender.hasPermission(PERMISSION)) {
@@ -109,15 +124,49 @@ public final class EquipmentAdminCommand implements TabExecutor, AutoCloseable {
     }
 
     private void configuration(CommandSender sender, String[] args) {
-        if (args.length < 2 || args.length > 3 || !args[1].equals("adventure-mode")
-                || args.length == 3 && !args[2].equals("true") && !args[2].equals("false")) {
-            sender.sendMessage("Usage: /fantasystick config adventure-mode [true|false]");
+        if (args.length < 2 || args.length > 3) { configurationUsage(sender); return; }
+        if (args[1].equals("adventure-mode")) { adventureConfiguration(sender, args); return; }
+        if (frostSettings == null || !games.dmg.fantasystick.persistence.FrostShardSettings.keys().contains(args[1])) {
+            configurationUsage(sender); return;
+        }
+        String key = args[1];
+        if (args.length == 2) {
+            sender.sendMessage(key + "=" + frostSettings.value(key) + " (applies to future Frost Shard casts only)");
             return;
         }
+        java.util.concurrent.CompletionStage<games.dmg.fantasystick.persistence.FrostShardSettings.Update> operation;
+        try { operation = frostSettings.set(key, args[2]); }
+        catch (IllegalArgumentException invalid) {
+            sender.sendMessage("Frost Shard setting is invalid; the effective value is unchanged."); return;
+        }
+        operation.whenComplete((saved, failure) -> {
+            if (failure != null) report(null, "config-" + key, failure);
+            if (closed) return;
+            try {
+                nextTick.accept(() -> {
+                    if (closed) return;
+                    if (failure == null) {
+                        frostShard.configure(saved.settings());
+                        abilities.replace(frostShard.definition());
+                        frostSettings.publish(saved);
+                    }
+                    if (!sender.hasPermission(PERMISSION)
+                            || sender instanceof org.bukkit.entity.Player player && !player.isOnline()) return;
+                    sender.sendMessage(failure == null
+                        ? "Saved " + key + "=" + saved.value() + " for future Frost Shard casts; active effects and deadlines are unchanged."
+                        : "Frost Shard configuration save failed; the effective setting is unchanged.");
+                });
+            } catch (RuntimeException rejected) { report(null, "config-response", rejected); }
+        });
+    }
+
+    private void adventureConfiguration(CommandSender sender, String[] args) {
+        if (args.length == 3 && !args[2].equals("true") && !args[2].equals("false")) {
+            sender.sendMessage("Usage: /fantasystick config adventure-mode [true|false]"); return;
+        }
         if (settings == null) { sender.sendMessage("Adventure configuration is unavailable."); return; }
         if (args.length == 2) {
-            sender.sendMessage("adventure-mode=" + settings.enabled() + " (applies to new sessions only)");
-            return;
+            sender.sendMessage("adventure-mode=" + settings.enabled() + " (applies to new sessions only)"); return;
         }
         settings.set(Boolean.parseBoolean(args[2])).whenComplete((saved, failure) -> {
             if (failure != null) report(null, "config-adventure-mode", failure);
@@ -134,6 +183,10 @@ public final class EquipmentAdminCommand implements TabExecutor, AutoCloseable {
         });
     }
 
+    private static void configurationUsage(CommandSender sender) {
+        sender.sendMessage("Usage: /fantasystick config <setting> [value]");
+    }
+
     private void report(UUID owner, String operation, Throwable cause) {
         try { diagnostics.accept(new Failure(owner, operation, cause)); }
         catch (RuntimeException ignored) { /* Diagnostics cannot authorize recovery. */ }
@@ -141,7 +194,26 @@ public final class EquipmentAdminCommand implements TabExecutor, AutoCloseable {
 
     // Never fall back to Bukkit's online-player-name suggestions for a UUID-only admin interface.
     @Override public List<String> onTabComplete(CommandSender sender, Command command, String alias, String[] args) {
+        if (closed || !sender.hasPermission(PERMISSION)) return List.of();
+        if (args.length == 1) return matching(List.of("config", "inspect", "recover"), args[0]);
+        if (args.length == 2 && args[0].equals("config")) {
+            var keys = new java.util.ArrayList<String>(); keys.add("adventure-mode");
+            keys.addAll(games.dmg.fantasystick.persistence.FrostShardSettings.keys());
+            return matching(keys, args[1]);
+        }
+        if (args.length == 3 && args[0].equals("config")) {
+            if (args[1].equals("adventure-mode")) return matching(List.of("false", "true"), args[2]);
+            if (frostSettings != null && games.dmg.fantasystick.persistence.FrostShardSettings.keys().contains(args[1])) {
+                String current = frostSettings.value(args[1]);
+                String defaults = games.dmg.fantasystick.persistence.FrostShardSettings.defaultValue(args[1]);
+                return matching(current.equals(defaults) ? List.of(current) : List.of(current, defaults), args[2]);
+            }
+        }
         return List.of();
     }
+
+    private static List<String> matching(java.util.Collection<String> values, String prefix) {
+        return values.stream().filter(value -> value.startsWith(prefix)).distinct().sorted().toList();
+    }
     @Override public void close() { closed = true; }
 }

src/main/resources/config.yml

@@ -21,3 +21,17 @@ fireball-base-damage: 6
 fireball-cooldown-seconds: 4
 fireball-range-blocks: 32
 fireball-lifetime-seconds: 5
+
+# Great Sword defaults from the reviewed starter catalogue.
+great-sword-base-damage: 7
+great-sword-recovery-seconds: 1.2
+
+# Frost Shard defaults from the reviewed remaining-development packet.
+# Admin command: /fantasystick config <key> [value]
+frost-shard-base-damage: 4
+frost-shard-cooldown-seconds: 5
+frost-shard-range-blocks: 32
+frost-shard-lifetime-seconds: 5
+frost-shard-projectile-speed-blocks-per-tick: 1
+frost-shard-slowness-amplifier: 0
+frost-shard-slowness-duration-seconds: 2

src/main/resources/plugin.yml

@@ -8,7 +8,7 @@ author: dmg.games
 commands:
   fantasystick:
     description: Inspect/recover equipment sessions or configure fantasy mode.
-    usage: /fantasystick <inspect|recover> <player-uuid> | config adventure-mode [true|false]
+    usage: /fantasystick <inspect|recover> <player-uuid> | config <setting> [value]
     permission: fantasystick.admin
 permissions:
   fantasystick.admin:

src/nativeTest/java/games/dmg/fantasystick/FrostShardNativeTest.java

@@ -0,0 +1,537 @@
+package games.dmg.fantasystick;
+
+import static org.junit.jupiter.api.Assertions.*;
+import static org.mockito.ArgumentMatchers.*;
+import static org.mockito.Mockito.*;
+
+import java.math.BigInteger;
+import java.nio.file.Path;
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.io.TempDir;
+
+class FrostShardNativeTest {
+    @TempDir Path data;
+    @BeforeAll static void bootstrap() throws Exception { NativeRuntime.bootstrap(); }
+
+    @Test void bookAcquisitionEquippedUseAndDirectHitDealDamageAndOwnedSlow() throws Exception {
+        try (var f = new FantasyStickLifecycleNativeTest.Fixture(data)) {
+            f.plugin.setEnabled(true);
+            var a = new FantasyStickLifecycleNativeTest.Actor(data);
+            withStats(data, a, 12, 10);
+            f.players.put(a.core.id, a.player); f.activate(a);
+
+            a.core.inventory.getInventory().setSelectedSlot(0); PartyBookNativeTest.open(f, a);
+            String book = PartyBookNativeTest.text(a).replaceAll("\\s+", "");
+            assertTrue(book.contains("FrostShard"), book); assertTrue(book.contains("INT12"), book);
+            assertTrue(book.contains("WIS10"), book); assertTrue(book.contains("SlownessI"), book);
+            var learn = abilityButton(a, "[Learn]", "frost_shard");
+            PartyBookNativeTest.click(f, a, learn); PartyBookNativeTest.click(f, a, learn);
+            PartyBookNativeTest.drain(f); PartyBookNativeTest.drain(f);
+            PartyBookNativeTest.click(f, a, abilityButton(a, "[3]", "frost_shard"));
+            PartyBookNativeTest.drain(f); PartyBookNativeTest.drain(f);
+            var storage = (games.dmg.fantasystick.persistence.CharacterStorage)
+                FantasyStickLifecycleNativeTest.Fixture.field(f.plugin, "characters");
+            var assigned = storage.find(a.core.record.id()).get().orElseThrow();
+            assertEquals(BigInteger.valueOf(39), assigned.unspentPoints());
+            assertTrue(assigned.learned().contains("frost_shard"));
+            assertEquals("frost_shard", assigned.loadout().getFirst());
+            assertEquals(org.bukkit.Material.PRISMARINE_SHARD, a.core.inventory.getItem(2).getType());
+
+            when(a.world.getUID()).thenReturn(java.util.UUID.randomUUID());
+            var eye = new org.bukkit.Location(a.world, 0, 65.6, 0);
+            eye.setDirection(new org.bukkit.util.Vector(1, 0, 0));
+            doReturn(eye).when(a.player).getEyeLocation();
+            var projectile = projectile(a, new org.bukkit.Location(a.world, 10, 65.6, 0));
+            doAnswer(call -> {
+                f.dispatcher.accept(new org.bukkit.event.entity.ProjectileLaunchEvent(projectile));
+                return projectile;
+            }).when(a.player).launchProjectile(eq(org.bukkit.entity.Snowball.class), any(org.bukkit.util.Vector.class));
+            a.core.inventory.getInventory().setSelectedSlot(2);
+            var cast = new org.bukkit.event.player.PlayerInteractEvent(a.player,
+                org.bukkit.event.block.Action.RIGHT_CLICK_AIR, a.core.inventory.getItem(2), null,
+                org.bukkit.block.BlockFace.SELF, org.bukkit.inventory.EquipmentSlot.HAND);
+            f.dispatcher.accept(cast); PartyBookNativeTest.drain(f); PartyBookNativeTest.drain(f);
+            assertEquals(org.bukkit.event.Event.Result.DENY, cast.useItemInHand());
+            verify(a.player).launchProjectile(eq(org.bukkit.entity.Snowball.class), any(org.bukkit.util.Vector.class));
+            var frost = FantasyStickLifecycleNativeTest.Fixture.field(f.plugin, "frostShard");
+            assertEquals(1, ((java.util.Map<?, ?>) FantasyStickLifecycleNativeTest.Fixture.field(frost, "projectiles")).size());
+
+            var target = mock(org.bukkit.entity.LivingEntity.class);
+            when(target.getUniqueId()).thenReturn(java.util.UUID.randomUUID());
+            when(target.getType()).thenReturn(org.bukkit.entity.EntityType.ZOMBIE);
+            when(target.getLocation()).thenReturn(new org.bukkit.Location(a.world, 10, 65.6, 0));
+            when(target.addPotionEffect(any())).thenReturn(true);
+            var damages = new java.util.ArrayList<org.bukkit.event.entity.EntityDamageByEntityEvent>();
+            doAnswer(call -> {
+                var source = (org.bukkit.damage.DamageSource) call.getArgument(1);
+                var event = new org.bukkit.event.entity.EntityDamageByEntityEvent(projectile, target,
+                    org.bukkit.event.entity.EntityDamageEvent.DamageCause.PROJECTILE, source,
+                    (Double) call.getArgument(0));
+                damages.add(event); f.dispatcher.accept(event); return null;
+            }).when(target).damage(anyDouble(), any(org.bukkit.damage.DamageSource.class));
+            var hit = new org.bukkit.event.entity.ProjectileHitEvent(projectile, target);
+            f.dispatcher.accept(hit);
+            assertFalse(hit.isCancelled(), "Eligible hostile Frost Shard hit was unexpectedly cancelled");
+            assertEquals(1, damages.size()); assertEquals(5.0, damages.getFirst().getDamage());
+            var effect = org.mockito.ArgumentCaptor.forClass(org.bukkit.potion.PotionEffect.class);
+            verify(target).addPotionEffect(effect.capture());
+            assertEquals(org.bukkit.potion.PotionEffectType.SLOWNESS, effect.getValue().getType());
+            assertEquals(40, effect.getValue().getDuration()); assertEquals(0, effect.getValue().getAmplifier());
+            f.dispatcher.accept(new org.bukkit.event.entity.EntityDeathEvent(target, damages.getFirst().getDamageSource(),
+                new java.util.ArrayList<>(), 0));
+            PartyBookNativeTest.drain(f); PartyBookNativeTest.drain(f);
+            assertEquals(BigInteger.TEN, storage.find(a.core.record.id()).get().orElseThrow().experience(),
+                "Accepted Frost Shard damage is attributed to the originating character");
+            assertNotNull(storage.find(a.core.record.id()).get().orElseThrow().cooldowns().get("frost_shard"));
+            f.dispatcher.accept(new org.bukkit.event.entity.ProjectileHitEvent(projectile, target));
+            assertEquals(1, damages.size());
+            verify(projectile, atLeastOnce()).remove();
+        }
+    }
+
+    @Test void partyMixedModeAndCancelledDamageApplyNeitherDamageNorSlow() throws Exception {
+        java.nio.file.Files.writeString(data.resolve("config.yml"), "frost-shard-cooldown-seconds: 0\n");
+        try (var f = new FantasyStickLifecycleNativeTest.Fixture(data)) {
+            f.plugin.setEnabled(true);
+            var a = new FantasyStickLifecycleNativeTest.Actor(data); var b = new FantasyStickLifecycleNativeTest.Actor(data);
+            withFrostShard(data, a, 12, 10);
+            f.players.put(a.core.id, a.player); f.players.put(b.core.id, b.player); f.activate(a); f.activate(b);
+            var parties = PartyLifecycleNativeTest.parties(f); var party = parties.create(a.core.id).orElseThrow();
+            assertTrue(parties.accept(b.core.id, parties.invite(a.core.id, party.id(), b.core.id).orElseThrow().id()));
+            when(a.world.getUID()).thenReturn(java.util.UUID.randomUUID());
+            var first = projectile(a, new org.bukkit.Location(a.world, 2, 65.6, 0));
+            var second = projectile(a, new org.bukkit.Location(a.world, 2, 65.6, 0));
+            var third = projectile(a, new org.bukkit.Location(a.world, 2, 65.6, 0));
+            prepareLaunches(f, a, first, second, third);
+
+            cast(f, a); var partyHit = new org.bukkit.event.entity.ProjectileHitEvent(first, b.player); f.dispatcher.accept(partyHit);
+            assertTrue(partyHit.isCancelled()); verify(b.player, never()).damage(anyDouble(), any(org.bukkit.damage.DamageSource.class));
+            var ordinary = mock(org.bukkit.entity.Player.class); when(ordinary.getUniqueId()).thenReturn(java.util.UUID.randomUUID());
+            cast(f, a); var ordinaryHit = new org.bukkit.event.entity.ProjectileHitEvent(second, ordinary); f.dispatcher.accept(ordinaryHit);
+            assertTrue(ordinaryHit.isCancelled()); verify(ordinary, never()).damage(anyDouble(), any(org.bukkit.damage.DamageSource.class));
+
+            var target = mock(org.bukkit.entity.LivingEntity.class); when(target.getUniqueId()).thenReturn(java.util.UUID.randomUUID());
+            when(target.getLocation()).thenReturn(new org.bukkit.Location(a.world, 2, 65.6, 0));
+            doAnswer(call -> {
+                var source = (org.bukkit.damage.DamageSource) call.getArgument(1);
+                var event = new org.bukkit.event.entity.EntityDamageByEntityEvent(third, target,
+                    org.bukkit.event.entity.EntityDamageEvent.DamageCause.PROJECTILE, source, (Double) call.getArgument(0));
+                event.setCancelled(true); f.dispatcher.accept(event); return null;
+            }).when(target).damage(anyDouble(), any(org.bukkit.damage.DamageSource.class));
+            cast(f, a); f.dispatcher.accept(new org.bukkit.event.entity.ProjectileHitEvent(third, target));
+            verify(target, never()).addPotionEffect(any());
+        }
+    }
+
+    @Test void rangeLifetimeAndSessionEndRemoveOwnedProjectilesWithoutLateDamage() throws Exception {
+        java.nio.file.Files.writeString(data.resolve("config.yml"), "frost-shard-cooldown-seconds: 0\n");
+        try (var f = new FantasyStickLifecycleNativeTest.Fixture(data)) {
+            f.plugin.setEnabled(true);
+            var a = new FantasyStickLifecycleNativeTest.Actor(data); withFrostShard(data, a, 12, 10);
+            f.players.put(a.core.id, a.player); f.activate(a); when(a.world.getUID()).thenReturn(java.util.UUID.randomUUID());
+            var outside = projectile(a, new org.bukkit.Location(a.world, 32.01, 65.6, 0));
+            var boundary = projectile(a, new org.bukkit.Location(a.world, 32, 65.6, 0));
+            var expiring = projectile(a, new org.bukkit.Location(a.world, 1, 65.6, 0));
+            var exiting = projectile(a, new org.bukkit.Location(a.world, 1, 65.6, 0));
+            prepareLaunches(f, a, outside, boundary, expiring, exiting);
+            var target = mock(org.bukkit.entity.LivingEntity.class); when(target.getUniqueId()).thenReturn(java.util.UUID.randomUUID());
+            when(target.addPotionEffect(any())).thenReturn(true);
+            var damages = new java.util.concurrent.atomic.AtomicInteger();
+            doAnswer(call -> {
+                damages.incrementAndGet();
+                var source = call.getArgument(1, org.bukkit.damage.DamageSource.class);
+                var projectile = source.getDirectEntity();
+                f.dispatcher.accept(new org.bukkit.event.entity.EntityDamageByEntityEvent(projectile, target,
+                    org.bukkit.event.entity.EntityDamageEvent.DamageCause.PROJECTILE, source, (Double) call.getArgument(0)));
+                return null;
+            }).when(target).damage(anyDouble(), any(org.bukkit.damage.DamageSource.class));
+
+            cast(f, a); f.dispatcher.accept(new org.bukkit.event.entity.ProjectileHitEvent(outside, target));
+            assertEquals(0, damages.get()); verify(outside, atLeastOnce()).remove();
+            cast(f, a); f.dispatcher.accept(new org.bukkit.event.entity.ProjectileHitEvent(boundary, target));
+            assertEquals(1, damages.get());
+            cast(f, a); f.delayed.getLast().run(); verify(expiring, atLeastOnce()).remove();
+            f.dispatcher.accept(new org.bukkit.event.entity.ProjectileHitEvent(expiring, target)); assertEquals(1, damages.get());
+            cast(f, a); a.core.inventory.setItemInOffHand(null); f.changed(a);
+            PartyBookNativeTest.drain(f); f.awaitCharacterAndReceipt(a);
+            ((games.dmg.fantasystick.ability.AbilityEngine) FantasyStickLifecycleNativeTest.Fixture.field(f.plugin, "abilityEngine")).sweep();
+            verify(exiting, atLeastOnce()).remove();
+        }
+    }
+
+    @Test void unlearnRelearnAndTransferRetainCooldownAndClearOwnedProjectile() throws Exception {
+        java.nio.file.Files.writeString(data.resolve("config.yml"), "frost-shard-cooldown-seconds: 60\n");
+        try (var f = new FantasyStickLifecycleNativeTest.Fixture(data)) {
+            f.plugin.setEnabled(true);
+            var a = new FantasyStickLifecycleNativeTest.Actor(data); withStats(data, a, 12, 10);
+            f.players.put(a.core.id, a.player); f.activate(a); learnAndAssign(f, a);
+            when(a.world.getUID()).thenReturn(java.util.UUID.randomUUID());
+            var projectile = projectile(a, new org.bukkit.Location(a.world, 2, 65.6, 0)); prepareLaunches(f, a, projectile);
+            cast(f, a);
+            var storage = (games.dmg.fantasystick.persistence.CharacterStorage)
+                FantasyStickLifecycleNativeTest.Fixture.field(f.plugin, "characters");
+            var deadline = storage.find(a.core.record.id()).get().orElseThrow().cooldowns().get("frost_shard");
+            assertNotNull(deadline);
+
+            a.core.inventory.getInventory().setSelectedSlot(0); PartyBookNativeTest.open(f, a);
+            var unlearn = abilityButton(a, "[Unlearn]", "frost_shard");
+            PartyBookNativeTest.click(f, a, unlearn); PartyBookNativeTest.click(f, a, unlearn);
+            PartyBookNativeTest.drain(f); PartyBookNativeTest.drain(f);
+            var refunded = storage.find(a.core.record.id()).get().orElseThrow();
+            assertEquals(BigInteger.valueOf(40), refunded.unspentPoints());
+            assertFalse(refunded.learned().contains("frost_shard"));
+            assertTrue(refunded.loadout().stream().noneMatch("frost_shard"::equals));
+            assertEquals(deadline, refunded.cooldowns().get("frost_shard"));
+            verify(projectile, atLeastOnce()).remove();
+
+            learnAndAssign(f, a); cast(f, a);
+            verify(a.player, times(1)).launchProjectile(eq(org.bukkit.entity.Snowball.class), any(org.bukkit.util.Vector.class));
+            assertTrue(a.messages.stream().anyMatch(message -> message.contains("ready in")));
+            var sheet = a.core.inventory.getItemInOffHand().clone();
+            a.core.inventory.setItemInOffHand(null); f.changed(a); PartyBookNativeTest.drain(f); f.awaitCharacterAndReceipt(a);
+            var b = new FantasyStickLifecycleNativeTest.Actor(data); b.core.inventory.setItemInOffHand(sheet);
+            f.players.put(b.core.id, b.player); f.activate(b); cast(f, b);
+            verify(b.player, never()).launchProjectile(eq(org.bukkit.entity.Snowball.class), any(org.bukkit.util.Vector.class));
+            assertTrue(b.messages.stream().anyMatch(message -> message.contains("ready in")));
+            assertEquals(deadline, storage.find(a.core.record.id()).get().orElseThrow().cooldowns().get("frost_shard"));
+        }
+    }
+
+    @Test void failedCooldownPersistenceLaunchesNoProjectileOrSlow() {
+        var storage = mock(games.dmg.fantasystick.persistence.CharacterStorage.class);
+        var sessions = mock(games.dmg.fantasystick.session.EquipmentSessions.class);
+        var parties = new games.dmg.fantasystick.party.PartyRoster(java.time.Clock.systemUTC(), ignored -> true);
+        var registry = new games.dmg.fantasystick.ability.AbilityRegistry();
+        var frost = new games.dmg.fantasystick.ability.FrostShard(
+            games.dmg.fantasystick.ability.FrostShard.Settings.defaults()); registry.register(frost.definition());
+        var base = new games.dmg.fantasystick.crafting.CharacterFactory().create(
+            games.dmg.fantasystick.progression.ProgressionRules.defaults());
+        var stats = new java.util.EnumMap<>(base.stats());
+        stats.put(games.dmg.fantasystick.progression.Stat.INT, BigInteger.valueOf(12));
+        stats.put(games.dmg.fantasystick.progression.Stat.WIS, BigInteger.TEN);
+        var record = new games.dmg.fantasystick.persistence.CharacterRecord(base.id(), base.name(), base.revision(), stats,
+            base.level(), base.experience(), base.unspentPoints(), base.health(), java.util.Set.of("frost_shard"),
+            java.util.List.of("frost_shard", "", "", "", "", "", ""), base.cooldowns(), base.restrictedKills(),
+            false, null, null);
+        var active = new games.dmg.fantasystick.session.EquipmentSessions.Active(java.util.UUID.randomUUID(),
+            java.util.UUID.randomUUID(), record.id());
+        var player = mock(org.bukkit.entity.Player.class);
+        when(sessions.current(active)).thenReturn(true); when(sessions.currentRecord(active)).thenReturn(java.util.Optional.of(record));
+        var failed = new java.util.concurrent.CompletableFuture<games.dmg.fantasystick.persistence.CharacterStorage.AbilityMutation>();
+        failed.completeExceptionally(new java.io.IOException("simulated Frost Shard cooldown failure"));
+        when(storage.commitAbilityCooldown(eq(record.id()), eq(record.revision()), eq("frost_shard"), any())).thenReturn(failed);
+        var failures = new java.util.ArrayList<games.dmg.fantasystick.ability.AbilityEngine.Failure>();
+        var engine = new games.dmg.fantasystick.ability.AbilityEngine(registry, storage, sessions, parties,
+            java.time.Clock.systemUTC(), Runnable::run, (delay, action) -> () -> {}, ignored -> {}, failures::add);
+        engine.accept(new games.dmg.fantasystick.session.ControlInput(player, active, 2, "frost_shard",
+            games.dmg.fantasystick.session.ControlInput.Kind.ABILITY,
+            games.dmg.fantasystick.session.ControlInput.Gesture.USE, null, 0, 0, () -> true));
+        verify(player, never()).launchProjectile(eq(org.bukkit.entity.Snowball.class), any(org.bukkit.util.Vector.class));
+        assertEquals(1, failures.size()); engine.close(); frost.close(); parties.close();
+    }
+
+    @Test void configuredDefinitionAndFormulaPreserveReviewedFiniteUncappedScaling() throws Exception {
+        java.nio.file.Files.writeString(data.resolve("config.yml"),
+            "frost-shard-base-damage: 9\nfrost-shard-cooldown-seconds: 2.5\n"
+                + "frost-shard-range-blocks: 40\nfrost-shard-lifetime-seconds: 7\n"
+                + "frost-shard-projectile-speed-blocks-per-tick: 2\n"
+                + "frost-shard-slowness-amplifier: 2\nfrost-shard-slowness-duration-seconds: 3\n");
+        try (var f = new FantasyStickLifecycleNativeTest.Fixture(data)) {
+            f.plugin.setEnabled(true);
+            var registry = (games.dmg.fantasystick.ability.AbilityRegistry)
+                FantasyStickLifecycleNativeTest.Fixture.field(f.plugin, "abilityRegistry");
+            var definition = registry.find("frost_shard").orElseThrow();
+            assertEquals(java.time.Duration.ofMillis(2500), definition.cooldown());
+            assertEquals(new java.math.BigDecimal("9"), definition.parameters().get("base-damage"));
+            assertEquals(0, new java.math.BigDecimal("40").compareTo(definition.parameters().get("range")));
+            assertEquals(0, new java.math.BigDecimal("7").compareTo(definition.parameters().get("lifetime")));
+            assertEquals(0, new java.math.BigDecimal("2").compareTo(definition.parameters().get("projectile-speed")));
+            assertEquals(0, new java.math.BigDecimal("2").compareTo(definition.parameters().get("slowness-amplifier")));
+            assertEquals(0, new java.math.BigDecimal("3").compareTo(definition.parameters().get("slowness-duration")));
+            var unavailable = new FantasyStickLifecycleNativeTest.Actor(data);
+            f.players.put(unavailable.core.id, unavailable.player); f.activate(unavailable);
+            unavailable.core.inventory.getInventory().setSelectedSlot(0); PartyBookNativeTest.open(f, unavailable);
+            assertTrue(PartyBookNativeTest.text(unavailable).replaceAll("\\s+", "")
+                .contains("Unavailable:requirements"));
+            assertThrows(AssertionError.class, () -> abilityButton(unavailable, "[Learn]", "frost_shard"));
+        }
+        assertEquals(BigInteger.valueOf(4), games.dmg.fantasystick.ability.FrostShard.damage(BigInteger.TEN));
+        assertEquals(BigInteger.valueOf(5), games.dmg.fantasystick.ability.FrostShard.damage(BigInteger.valueOf(12)));
+        assertEquals(BigInteger.TEN.pow(500).subtract(BigInteger.TEN).divide(BigInteger.TWO).add(BigInteger.valueOf(4)),
+            games.dmg.fantasystick.ability.FrostShard.damage(BigInteger.TEN.pow(500)));
+    }
+
+    @Test void invalidPackagedFrostSettingsFailBeforeInstallingGameplay() throws Exception {
+        for (String configuration : java.util.List.of("frost-shard-base-damage: -1\n",
+                "frost-shard-cooldown-seconds: 31536001\n", "frost-shard-range-blocks: 0\n",
+                "frost-shard-lifetime-seconds: 0\n", "frost-shard-projectile-speed-blocks-per-tick: 0\n",
+                "frost-shard-slowness-amplifier: 256\n", "frost-shard-slowness-duration-seconds: 0\n")) {
+            var directory = data.resolve(Integer.toHexString(configuration.hashCode()));
+            java.nio.file.Files.createDirectories(directory); java.nio.file.Files.writeString(directory.resolve("config.yml"), configuration);
+            try (var f = new FantasyStickLifecycleNativeTest.Fixture(directory)) {
+                assertThrows(IllegalArgumentException.class, () -> f.plugin.setEnabled(true));
+                assertTrue(f.order.isEmpty()); assertTrue(f.recipes.isEmpty());
+                assertFalse(java.nio.file.Files.exists(directory.resolve("characters")));
+            }
+        }
+    }
+
+    @Test void sourceExitRemovesOnlyOwnedSlowAndRestoresThePriorNativeLayer() throws Exception {
+        java.nio.file.Files.writeString(data.resolve("config.yml"), "frost-shard-cooldown-seconds: 0\n");
+        try (var f = new FantasyStickLifecycleNativeTest.Fixture(data)) {
+            f.plugin.setEnabled(true);
+            var a = new FantasyStickLifecycleNativeTest.Actor(data); withFrostShard(data, a, 12, 10);
+            f.players.put(a.core.id, a.player); f.activate(a);
+            when(a.world.getUID()).thenReturn(java.util.UUID.randomUUID());
+            var eye = new org.bukkit.Location(a.world, 0, 65.6, 0); eye.setDirection(new org.bukkit.util.Vector(1, 0, 0));
+            doReturn(eye).when(a.player).getEyeLocation();
+            var projectile = projectile(a, new org.bukkit.Location(a.world, 2, 65.6, 0));
+            doAnswer(call -> { f.dispatcher.accept(new org.bukkit.event.entity.ProjectileLaunchEvent(projectile)); return projectile; })
+                .when(a.player).launchProjectile(eq(org.bukkit.entity.Snowball.class), any(org.bukkit.util.Vector.class));
+            var target = mock(org.bukkit.entity.LivingEntity.class);
+            when(target.getUniqueId()).thenReturn(java.util.UUID.randomUUID());
+            when(target.getLocation()).thenReturn(new org.bukkit.Location(a.world, 2, 65.6, 0));
+            var previous = new org.bukkit.potion.PotionEffect(org.bukkit.potion.PotionEffectType.SLOWNESS, 200, 1);
+            var current = new java.util.concurrent.atomic.AtomicReference<org.bukkit.potion.PotionEffect>(previous);
+            when(target.getPotionEffect(org.bukkit.potion.PotionEffectType.SLOWNESS)).thenAnswer(call -> current.get());
+            when(target.addPotionEffect(any())).thenAnswer(call -> { current.set(call.getArgument(0)); return true; });
+            doAnswer(call -> { current.set(null); return null; }).when(target)
+                .removePotionEffect(org.bukkit.potion.PotionEffectType.SLOWNESS);
+            doAnswer(call -> {
+                var source = (org.bukkit.damage.DamageSource) call.getArgument(1);
+                f.dispatcher.accept(new org.bukkit.event.entity.EntityDamageByEntityEvent(projectile, target,
+                    org.bukkit.event.entity.EntityDamageEvent.DamageCause.PROJECTILE, source,
+                    (Double) call.getArgument(0))); return null;
+            }).when(target).damage(anyDouble(), any(org.bukkit.damage.DamageSource.class));
+            a.core.inventory.getInventory().setSelectedSlot(2);
+            f.dispatcher.accept(new org.bukkit.event.player.PlayerInteractEvent(a.player,
+                org.bukkit.event.block.Action.RIGHT_CLICK_AIR, a.core.inventory.getItem(2), null,
+                org.bukkit.block.BlockFace.SELF, org.bukkit.inventory.EquipmentSlot.HAND));
+            PartyBookNativeTest.drain(f); PartyBookNativeTest.drain(f);
+            f.dispatcher.accept(new org.bukkit.event.entity.ProjectileHitEvent(projectile, target));
+            assertEquals(0, current.get().getAmplifier());
+            a.core.inventory.setItemInOffHand(null); f.changed(a); PartyBookNativeTest.drain(f); f.awaitCharacterAndReceipt(a);
+            ((games.dmg.fantasystick.ability.AbilityEngine) FantasyStickLifecycleNativeTest.Fixture.field(f.plugin, "abilityEngine")).sweep();
+            assertNotNull(current.get()); assertEquals(1, current.get().getAmplifier());
+            assertTrue(current.get().getDuration() > 0 && current.get().getDuration() <= 200);
+        }
+    }
+
+    @Test void reenableWaitsForAcceptedFrostConfigurationBeforeInstallingGameplay() throws Exception {
+        try (var f = new FantasyStickLifecycleNativeTest.Fixture(data)) {
+            f.plugin.setEnabled(true);
+            var settings = FantasyStickLifecycleNativeTest.Fixture.field(f.plugin, "frostShardSettings");
+            var worker = (java.util.concurrent.ExecutorService) FantasyStickLifecycleNativeTest.Fixture.field(settings, "worker");
+            var entered = new java.util.concurrent.CountDownLatch(1); var release = new java.util.concurrent.CountDownLatch(1);
+            worker.execute(() -> {
+                entered.countDown();
+                try { release.await(5, java.util.concurrent.TimeUnit.SECONDS); }
+                catch (InterruptedException failure) { Thread.currentThread().interrupt(); }
+            });
+            try {
+                assertTrue(entered.await(5, java.util.concurrent.TimeUnit.SECONDS));
+                var sender = new EquipmentAdminCommandNativeTest.Sender();
+                f.command.execute(sender.port, "fantasystick", new String[]{"config", "frost-shard-base-damage", "9"});
+                f.plugin.setEnabled(false); f.plugin.setEnabled(true);
+                assertNull(FantasyStickLifecycleNativeTest.Fixture.field(f.plugin, "sessions"));
+                release.countDown(); f.tick();
+                var registry = (games.dmg.fantasystick.ability.AbilityRegistry)
+                    FantasyStickLifecycleNativeTest.Fixture.field(f.plugin, "abilityRegistry");
+                assertEquals(new java.math.BigDecimal("9"), registry.find("frost_shard").orElseThrow()
+                    .parameters().get("base-damage"));
+            } finally { release.countDown(); }
+        }
+    }
+
+    @Test void failedAdminPersistenceLeavesTheEffectiveDefinitionAndExternalFileUnchanged() throws Exception {
+        try (var f = new FantasyStickLifecycleNativeTest.Fixture(data)) {
+            f.plugin.setEnabled(true);
+            var outside = data.resolveSibling(data.getFileName() + "-frost-outside");
+            java.nio.file.Files.writeString(outside, "untouched\n");
+            java.nio.file.Files.createSymbolicLink(data.resolve("config.yml"), outside);
+            var sender = new EquipmentAdminCommandNativeTest.Sender();
+            f.command.execute(sender.port, "fantasystick", new String[]{"config", "frost-shard-base-damage", "9"});
+            var response = f.tasks.poll(5, java.util.concurrent.TimeUnit.SECONDS); assertNotNull(response); response.run();
+            assertTrue(sender.messages.getLast().contains("save failed"));
+            var registry = (games.dmg.fantasystick.ability.AbilityRegistry)
+                FantasyStickLifecycleNativeTest.Fixture.field(f.plugin, "abilityRegistry");
+            assertEquals(new java.math.BigDecimal("4"), registry.find("frost_shard").orElseThrow()
+                .parameters().get("base-damage"));
+            assertEquals("untouched\n", java.nio.file.Files.readString(outside));
+            java.nio.file.Files.delete(data.resolve("config.yml")); java.nio.file.Files.delete(outside);
+        }
+    }
+
+    @Test void acknowledgedUpdatesAffectFutureCastsButNotAnActiveProjectileSnapshot() throws Exception {
+        java.nio.file.Files.writeString(data.resolve("config.yml"), "frost-shard-cooldown-seconds: 0\n");
+        try (var f = new FantasyStickLifecycleNativeTest.Fixture(data)) {
+            f.plugin.setEnabled(true);
+            var a = new FantasyStickLifecycleNativeTest.Actor(data); withFrostShard(data, a, 12, 10);
+            f.players.put(a.core.id, a.player); f.activate(a); when(a.world.getUID()).thenReturn(java.util.UUID.randomUUID());
+            var oldProjectile = projectile(a, new org.bukkit.Location(a.world, 2, 65.6, 0));
+            var newProjectile = projectile(a, new org.bukkit.Location(a.world, 2, 65.6, 0));
+            prepareLaunches(f, a, oldProjectile, newProjectile); cast(f, a);
+
+            var sender = new EquipmentAdminCommandNativeTest.Sender();
+            f.command.execute(sender.port, "fantasystick", new String[]{"config", "frost-shard-base-damage", "9"});
+            var response = f.tasks.poll(5, java.util.concurrent.TimeUnit.SECONDS); assertNotNull(response); response.run();
+            var target = mock(org.bukkit.entity.LivingEntity.class); when(target.getUniqueId()).thenReturn(java.util.UUID.randomUUID());
+            when(target.getLocation()).thenReturn(new org.bukkit.Location(a.world, 2, 65.6, 0)); when(target.addPotionEffect(any())).thenReturn(true);
+            var damages = new java.util.ArrayList<Double>();
+            doAnswer(call -> {
+                damages.add(call.getArgument(0)); var source = call.getArgument(1, org.bukkit.damage.DamageSource.class);
+                f.dispatcher.accept(new org.bukkit.event.entity.EntityDamageByEntityEvent(source.getDirectEntity(), target,
+                    org.bukkit.event.entity.EntityDamageEvent.DamageCause.PROJECTILE, source, (Double) call.getArgument(0)));
+                return null;
+            }).when(target).damage(anyDouble(), any(org.bukkit.damage.DamageSource.class));
+            f.dispatcher.accept(new org.bukkit.event.entity.ProjectileHitEvent(oldProjectile, target));
+            cast(f, a); f.dispatcher.accept(new org.bukkit.event.entity.ProjectileHitEvent(newProjectile, target));
+            assertEquals(java.util.List.of(5.0, 10.0), damages);
+        }
+    }
+
+    @Test void administratorCanReadUpdateAndCompleteEveryFrostShardSetting() throws Exception {
+        try (var f = new FantasyStickLifecycleNativeTest.Fixture(data)) {
+            f.plugin.setEnabled(true);
+            var sender = new EquipmentAdminCommandNativeTest.Sender();
+            assertEquals(java.util.List.of("frost-shard-base-damage"),
+                f.command.tabComplete(sender.port, "fantasystick", new String[]{"config", "frost-shard-b"}));
+            assertEquals(java.util.List.of("frost-shard-base-damage", "frost-shard-cooldown-seconds",
+                "frost-shard-lifetime-seconds", "frost-shard-projectile-speed-blocks-per-tick",
+                "frost-shard-range-blocks", "frost-shard-slowness-amplifier",
+                "frost-shard-slowness-duration-seconds"),
+                f.command.tabComplete(sender.port, "fantasystick", new String[]{"config", "frost-shard-"}));
+            assertEquals(java.util.List.of("4"), f.command.tabComplete(sender.port, "fantasystick",
+                new String[]{"config", "frost-shard-base-damage", ""}));
+            assertTrue(f.command.tabComplete(sender.port, "fantasystick", new String[]{"config", "unknown"}).isEmpty());
+            sender.allowed = false;
+            assertTrue(f.command.tabComplete(sender.port, "fantasystick", new String[]{"config", "frost"}).isEmpty());
+            sender.allowed = true;
+
+            f.command.execute(sender.port, "fantasystick", new String[]{"config", "frost-shard-base-damage"});
+            assertTrue(sender.messages.getLast().contains("frost-shard-base-damage=4"));
+            sender.messages.clear();
+            f.command.execute(sender.port, "fantasystick", new String[]{"config", "frost-shard-base-damage", "9"});
+            assertTrue(sender.messages.isEmpty(), "Do not publish settings before durable acknowledgment");
+            var response = f.tasks.poll(5, java.util.concurrent.TimeUnit.SECONDS); assertNotNull(response); response.run();
+            assertTrue(sender.messages.getLast().contains("frost-shard-base-damage=9"));
+            var registry = (games.dmg.fantasystick.ability.AbilityRegistry)
+                FantasyStickLifecycleNativeTest.Fixture.field(f.plugin, "abilityRegistry");
+            assertEquals(new java.math.BigDecimal("9"), registry.find("frost_shard").orElseThrow()
+                .parameters().get("base-damage"));
+            var saved = (java.util.Map<?, ?>) new org.yaml.snakeyaml.Yaml().load(
+                java.nio.file.Files.readString(data.resolve("config.yml")));
+            assertEquals("9", String.valueOf(saved.get("frost-shard-base-damage")));
+
+            for (String invalid : java.util.List.of("-1", "1.5", "nope")) {
+                f.command.execute(sender.port, "fantasystick",
+                    new String[]{"config", "frost-shard-base-damage", invalid});
+                assertTrue(sender.messages.getLast().contains("invalid"));
+            }
+            assertEquals(new java.math.BigDecimal("9"), registry.find("frost_shard").orElseThrow()
+                .parameters().get("base-damage"));
+            f.plugin.setEnabled(false); f.plugin.setEnabled(true);
+            var reloaded = (games.dmg.fantasystick.ability.AbilityRegistry)
+                FantasyStickLifecycleNativeTest.Fixture.field(f.plugin, "abilityRegistry");
+            assertEquals(new java.math.BigDecimal("9"), reloaded.find("frost_shard").orElseThrow()
+                .parameters().get("base-damage"));
+            sender.messages.clear();
+            f.command.execute(sender.port, "fantasystick", new String[]{"config", "frost-shard-base-damage"});
+            assertTrue(sender.messages.getLast().contains("=9"));
+        }
+    }
+
+    private static void learnAndAssign(FantasyStickLifecycleNativeTest.Fixture fixture,
+                                       FantasyStickLifecycleNativeTest.Actor actor) throws Exception {
+        actor.core.inventory.getInventory().setSelectedSlot(0); PartyBookNativeTest.open(fixture, actor);
+        PartyBookNativeTest.click(fixture, actor, abilityButton(actor, "[Learn]", "frost_shard"));
+        PartyBookNativeTest.drain(fixture); PartyBookNativeTest.drain(fixture);
+        PartyBookNativeTest.click(fixture, actor, abilityButton(actor, "[3]", "frost_shard"));
+        PartyBookNativeTest.drain(fixture); PartyBookNativeTest.drain(fixture);
+    }
+
+    private static void cast(FantasyStickLifecycleNativeTest.Fixture fixture,
+                             FantasyStickLifecycleNativeTest.Actor actor) throws Exception {
+        actor.core.inventory.getInventory().setSelectedSlot(2);
+        fixture.dispatcher.accept(new org.bukkit.event.player.PlayerInteractEvent(actor.player,
+            org.bukkit.event.block.Action.RIGHT_CLICK_AIR, actor.core.inventory.getItem(2), null,
+            org.bukkit.block.BlockFace.SELF, org.bukkit.inventory.EquipmentSlot.HAND));
+        PartyBookNativeTest.drain(fixture); PartyBookNativeTest.drain(fixture);
+    }
+
+    private static void prepareLaunches(FantasyStickLifecycleNativeTest.Fixture fixture,
+                                        FantasyStickLifecycleNativeTest.Actor actor,
+                                        org.bukkit.entity.Snowball... projectiles) {
+        var eye = new org.bukkit.Location(actor.world, 0, 65.6, 0);
+        eye.setDirection(new org.bukkit.util.Vector(1, 0, 0)); doReturn(eye).when(actor.player).getEyeLocation();
+        var queue = new java.util.ArrayDeque<>(java.util.List.of(projectiles));
+        doAnswer(call -> {
+            var projectile = queue.removeFirst(); fixture.dispatcher.accept(new org.bukkit.event.entity.ProjectileLaunchEvent(projectile));
+            return projectile;
+        }).when(actor.player).launchProjectile(eq(org.bukkit.entity.Snowball.class), any(org.bukkit.util.Vector.class));
+    }
+
+    private static net.minecraft.network.chat.ClickEvent.Custom abilityButton(
+            FantasyStickLifecycleNativeTest.Actor actor, String label, String ability) {
+        var book = org.bukkit.craftbukkit.inventory.CraftItemStack.asNMSCopy(actor.books.getLast())
+            .get(net.minecraft.core.component.DataComponents.WRITTEN_BOOK_CONTENT);
+        assertNotNull(book);
+        for (var page : book.pages()) {
+            var found = abilityButton(page.raw(), label, ability);
+            if (found != null) return found;
+        }
+        throw new AssertionError("Missing " + label + " action for " + ability);
+    }
+
+    private static net.minecraft.network.chat.ClickEvent.Custom abilityButton(
+            net.minecraft.network.chat.Component component, String label, String ability) {
+        if (component.getString().equals(label)
+                && component.getStyle().getClickEvent() instanceof net.minecraft.network.chat.ClickEvent.Custom custom
+                && custom.payload().orElse(null) instanceof net.minecraft.nbt.StringTag payload
+                && payload.value().contains(":" + ability)) return custom;
+        for (var child : component.getSiblings()) {
+            var found = abilityButton(child, label, ability);
+            if (found != null) return found;
+        }
+        return null;
+    }
+
+    private static void withFrostShard(Path data, FantasyStickLifecycleNativeTest.Actor actor,
+                                       int intelligence, int wisdom) throws Exception {
+        var repository = new games.dmg.fantasystick.persistence.YamlCharacterRepository(data);
+        var old = repository.load(actor.core.record.id()).orElseThrow();
+        var stats = new java.util.EnumMap<>(old.stats());
+        stats.put(games.dmg.fantasystick.progression.Stat.INT, BigInteger.valueOf(intelligence));
+        stats.put(games.dmg.fantasystick.progression.Stat.WIS, BigInteger.valueOf(wisdom));
+        repository.replace(new games.dmg.fantasystick.persistence.CharacterRecord(old.id(), old.name(),
+            old.revision().add(BigInteger.ONE), stats, old.level(), old.experience(), old.unspentPoints(), old.health(),
+            java.util.Set.of("frost_shard"), java.util.List.of("frost_shard", "", "", "", "", "", ""),
+            old.cooldowns(), old.restrictedKills(), false, null, null), old.revision());
+    }
+
+    private static void withStats(Path data, FantasyStickLifecycleNativeTest.Actor actor,
+                                  int intelligence, int wisdom) throws Exception {
+        var repository = new games.dmg.fantasystick.persistence.YamlCharacterRepository(data);
+        var old = repository.load(actor.core.record.id()).orElseThrow();
+        var stats = new java.util.EnumMap<>(old.stats());
+        stats.put(games.dmg.fantasystick.progression.Stat.INT, BigInteger.valueOf(intelligence));
+        stats.put(games.dmg.fantasystick.progression.Stat.WIS, BigInteger.valueOf(wisdom));
+        repository.replace(new games.dmg.fantasystick.persistence.CharacterRecord(old.id(), old.name(),
+            old.revision().add(BigInteger.ONE), stats, old.level(), old.experience(), old.unspentPoints(), old.health(),
+            old.learned(), old.loadout(), old.cooldowns(), old.restrictedKills(), false, null, null), old.revision());
+    }
+
+    private static org.bukkit.entity.Snowball projectile(FantasyStickLifecycleNativeTest.Actor actor,
+                                                          org.bukkit.Location location) {
+        var projectile = mock(org.bukkit.entity.Snowball.class);
+        when(projectile.getUniqueId()).thenReturn(java.util.UUID.randomUUID());
+        when(projectile.getShooter()).thenReturn(actor.player);
+        when(projectile.getLocation()).thenAnswer(ignored -> location.clone());
+        when(projectile.getWorld()).thenReturn(location.getWorld());
+        when(projectile.getPersistentDataContainer()).thenReturn(
+            new org.bukkit.craftbukkit.persistence.CraftPersistentDataContainer(
+                new org.bukkit.craftbukkit.persistence.CraftPersistentDataTypeRegistry()));
+        return projectile;
+    }
+}

src/nativeTest/java/games/dmg/fantasystick/GreatSwordNativeTest.java

@@ -0,0 +1,369 @@
+package games.dmg.fantasystick;
+
+import static org.junit.jupiter.api.Assertions.*;
+import static org.mockito.ArgumentMatchers.*;
+import static org.mockito.Mockito.*;
+
+import java.math.BigInteger;
+import java.nio.file.Path;
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.io.TempDir;
+
+class GreatSwordNativeTest {
+    @TempDir Path data;
+    @BeforeAll static void bootstrap() throws Exception { NativeRuntime.bootstrap(); }
+
+    @Test void bookAcquisitionAndFullyChargedEquippedStrikeReplaceVanillaDamage() throws Exception {
+        try (var f = new FantasyStickLifecycleNativeTest.Fixture(data)) {
+            f.plugin.setEnabled(true);
+            var a = new FantasyStickLifecycleNativeTest.Actor(data);
+            withStrength(data, a, 12);
+            f.players.put(a.core.id, a.player); f.activate(a);
+
+            a.core.inventory.getInventory().setSelectedSlot(0);
+            PartyBookNativeTest.open(f, a);
+            String book = PartyBookNativeTest.text(a);
+            assertTrue(book.contains("Great Sword"));
+            assertTrue(book.contains("STR 12"));
+            assertTrue(book.contains("1.2"));
+            var learn = abilityButton(a, "[Learn]", "great_sword");
+            PartyBookNativeTest.click(f, a, learn); PartyBookNativeTest.click(f, a, learn);
+            PartyBookNativeTest.drain(f); PartyBookNativeTest.drain(f);
+            PartyBookNativeTest.click(f, a, abilityButton(a, "[3]", "great_sword"));
+            PartyBookNativeTest.drain(f); PartyBookNativeTest.drain(f);
+
+            var storage = (games.dmg.fantasystick.persistence.CharacterStorage)
+                FantasyStickLifecycleNativeTest.Fixture.field(f.plugin, "characters");
+            var assigned = storage.find(a.core.record.id()).get().orElseThrow();
+            assertTrue(assigned.learned().contains("great_sword"));
+            assertEquals("great_sword", assigned.loadout().getFirst());
+            assertEquals(BigInteger.valueOf(39), assigned.unspentPoints());
+            assertEquals(org.bukkit.Material.WOODEN_SWORD, a.core.inventory.getItem(2).getType());
+
+            when(a.player.getAttackCooldown()).thenReturn(1.0f);
+            var target = mock(org.bukkit.entity.LivingEntity.class);
+            when(target.getUniqueId()).thenReturn(java.util.UUID.randomUUID());
+            when(target.getType()).thenReturn(org.bukkit.entity.EntityType.ZOMBIE);
+            when(a.world.getUID()).thenReturn(java.util.UUID.randomUUID());
+            when(target.getLocation()).thenReturn(new org.bukkit.Location(a.world, 4, 64, 0));
+            var damages = new java.util.ArrayList<org.bukkit.event.entity.EntityDamageByEntityEvent>();
+            doAnswer(call -> {
+                var source = (org.bukkit.damage.DamageSource) call.getArgument(1);
+                var event = new org.bukkit.event.entity.EntityDamageByEntityEvent(a.player, target,
+                    org.bukkit.event.entity.EntityDamageEvent.DamageCause.ENTITY_ATTACK, source,
+                    (Double) call.getArgument(0));
+                damages.add(event); f.dispatcher.accept(event); return null;
+            }).when(target).damage(anyDouble(), any(org.bukkit.damage.DamageSource.class));
+
+            a.core.inventory.getInventory().setSelectedSlot(2);
+            var before = java.time.Instant.now();
+            var attack = new io.papermc.paper.event.player.PrePlayerAttackEntityEvent(a.player, target, true);
+            f.dispatcher.accept(attack);
+            assertTrue(attack.isCancelled(), "The bound sword must never continue into vanilla damage");
+            PartyBookNativeTest.drain(f); PartyBookNativeTest.drain(f);
+            assertEquals(1, damages.size());
+            assertEquals(8.0, damages.getFirst().getDamage());
+            assertSame(a.player, damages.getFirst().getDamager());
+            assertEquals(org.bukkit.damage.DamageType.PLAYER_ATTACK, damages.getFirst().getDamageSource().getDamageType());
+
+            var saved = storage.find(a.core.record.id()).get().orElseThrow();
+            var deadline = saved.cooldowns().get("great_sword");
+            assertNotNull(deadline);
+            assertFalse(deadline.isBefore(before.plusMillis(1200)));
+            assertFalse(deadline.isAfter(java.time.Instant.now().plusMillis(1200)));
+            f.dispatcher.accept(new org.bukkit.event.entity.EntityDeathEvent(target, damages.getFirst().getDamageSource(),
+                new java.util.ArrayList<>(), 0));
+            PartyBookNativeTest.drain(f); PartyBookNativeTest.drain(f);
+            assertEquals(BigInteger.TEN, storage.find(a.core.record.id()).get().orElseThrow().experience(),
+                "Accepted direct damage is attributed to the originating character");
+            f.dispatcher.accept(new io.papermc.paper.event.player.PrePlayerAttackEntityEvent(a.player, target, true));
+            PartyBookNativeTest.drain(f);
+            assertEquals(1, damages.size(), "The persisted recovery prevents a repeated strike");
+            assertTrue(a.messages.stream().anyMatch(message -> message.contains("ready in")));
+        }
+    }
+
+    @Test void partialChargeUsesTheApprovedNativeCurveWithoutVanillaContinuation() throws Exception {
+        java.nio.file.Files.writeString(data.resolve("config.yml"), "great-sword-recovery-seconds: 0\n");
+        try (var f = new FantasyStickLifecycleNativeTest.Fixture(data)) {
+            f.plugin.setEnabled(true);
+            var a = new FantasyStickLifecycleNativeTest.Actor(data);
+            withGreatSword(data, a, 12);
+            f.players.put(a.core.id, a.player); f.activate(a);
+            when(a.player.getAttackCooldown()).thenReturn(0.5f);
+            var target = mock(org.bukkit.entity.LivingEntity.class);
+            when(target.getUniqueId()).thenReturn(java.util.UUID.randomUUID());
+            var damages = new java.util.ArrayList<Double>();
+            doAnswer(call -> {
+                double amount = call.getArgument(0); damages.add(amount);
+                var source = (org.bukkit.damage.DamageSource) call.getArgument(1);
+                f.dispatcher.accept(new org.bukkit.event.entity.EntityDamageByEntityEvent(a.player, target,
+                    org.bukkit.event.entity.EntityDamageEvent.DamageCause.ENTITY_ATTACK, source, amount));
+                return null;
+            }).when(target).damage(anyDouble(), any(org.bukkit.damage.DamageSource.class));
+            a.core.inventory.getInventory().setSelectedSlot(2);
+            var attack = new io.papermc.paper.event.player.PrePlayerAttackEntityEvent(a.player, target, true);
+            f.dispatcher.accept(attack); PartyBookNativeTest.drain(f); PartyBookNativeTest.drain(f);
+            assertTrue(attack.isCancelled());
+            assertEquals(java.util.List.of(3.2), damages);
+        }
+    }
+
+    @Test void refusedPlayersAndCancelledNativeDamagePreserveProtectionWithoutFreeVanillaHits() throws Exception {
+        try (var f = new FantasyStickLifecycleNativeTest.Fixture(data)) {
+            f.plugin.setEnabled(true);
+            var a = new FantasyStickLifecycleNativeTest.Actor(data);
+            var b = new FantasyStickLifecycleNativeTest.Actor(data);
+            withGreatSword(data, a, 12);
+            f.players.put(a.core.id, a.player); f.players.put(b.core.id, b.player);
+            f.activate(a); f.activate(b);
+            var parties = PartyLifecycleNativeTest.parties(f);
+            var party = parties.create(a.core.id).orElseThrow();
+            assertTrue(parties.accept(b.core.id,
+                parties.invite(a.core.id, party.id(), b.core.id).orElseThrow().id()));
+            when(a.player.getAttackCooldown()).thenReturn(1.0f);
+            a.core.inventory.getInventory().setSelectedSlot(2);
+
+            var partyAttack = new io.papermc.paper.event.player.PrePlayerAttackEntityEvent(a.player, b.player, true);
+            f.dispatcher.accept(partyAttack); PartyBookNativeTest.drain(f);
+            assertTrue(partyAttack.isCancelled());
+            verify(b.player, never()).damage(anyDouble(), any(org.bukkit.damage.DamageSource.class));
+
+            var ordinary = mock(org.bukkit.entity.Player.class);
+            when(ordinary.getUniqueId()).thenReturn(java.util.UUID.randomUUID());
+            var ordinaryAttack = new io.papermc.paper.event.player.PrePlayerAttackEntityEvent(a.player, ordinary, true);
+            f.dispatcher.accept(ordinaryAttack); PartyBookNativeTest.drain(f);
+            assertTrue(ordinaryAttack.isCancelled());
+            verify(ordinary, never()).damage(anyDouble(), any(org.bukkit.damage.DamageSource.class));
+
+            var target = mock(org.bukkit.entity.LivingEntity.class);
+            when(target.getUniqueId()).thenReturn(java.util.UUID.randomUUID());
+            when(target.getType()).thenReturn(org.bukkit.entity.EntityType.ZOMBIE);
+            when(a.world.getUID()).thenReturn(java.util.UUID.randomUUID());
+            when(target.getLocation()).thenReturn(new org.bukkit.Location(a.world, 4, 64, 0));
+            var damage = new java.util.concurrent.atomic.AtomicReference<org.bukkit.event.entity.EntityDamageByEntityEvent>();
+            doAnswer(call -> {
+                var source = (org.bukkit.damage.DamageSource) call.getArgument(1);
+                var event = new org.bukkit.event.entity.EntityDamageByEntityEvent(a.player, target,
+                    org.bukkit.event.entity.EntityDamageEvent.DamageCause.ENTITY_ATTACK, source,
+                    (Double) call.getArgument(0));
+                event.setCancelled(true); damage.set(event); f.dispatcher.accept(event); return null;
+            }).when(target).damage(anyDouble(), any(org.bukkit.damage.DamageSource.class));
+            f.dispatcher.accept(new io.papermc.paper.event.player.PrePlayerAttackEntityEvent(a.player, target, true));
+            PartyBookNativeTest.drain(f); PartyBookNativeTest.drain(f);
+            assertNotNull(damage.get()); assertTrue(damage.get().isCancelled());
+            var storage = (games.dmg.fantasystick.persistence.CharacterStorage)
+                FantasyStickLifecycleNativeTest.Fixture.field(f.plugin, "characters");
+            assertNotNull(storage.find(a.core.record.id()).get().orElseThrow().cooldowns().get("great_sword"),
+                "An acknowledged recovery is not refunded by later native cancellation");
+            f.dispatcher.accept(new org.bukkit.event.entity.EntityDeathEvent(target, damage.get().getDamageSource(),
+                new java.util.ArrayList<>(), 0));
+            PartyBookNativeTest.drain(f);
+            assertEquals(BigInteger.ZERO, storage.find(a.core.record.id()).get().orElseThrow().experience());
+        }
+    }
+
+    @Test void unlearnRelearnAndWholeCharacterTransferRetainTheOriginalRecovery() throws Exception {
+        java.nio.file.Files.writeString(data.resolve("config.yml"), "great-sword-recovery-seconds: 60\n");
+        try (var f = new FantasyStickLifecycleNativeTest.Fixture(data)) {
+            f.plugin.setEnabled(true);
+            var a = new FantasyStickLifecycleNativeTest.Actor(data); withStrength(data, a, 12);
+            f.players.put(a.core.id, a.player); f.activate(a);
+            learnAndAssign(f, a);
+            when(a.player.getAttackCooldown()).thenReturn(1.0f);
+            var target = mock(org.bukkit.entity.LivingEntity.class);
+            when(target.getUniqueId()).thenReturn(java.util.UUID.randomUUID());
+            var hits = new java.util.concurrent.atomic.AtomicInteger();
+            doAnswer(call -> {
+                hits.incrementAndGet();
+                var source = (org.bukkit.damage.DamageSource) call.getArgument(1);
+                f.dispatcher.accept(new org.bukkit.event.entity.EntityDamageByEntityEvent(a.player, target,
+                    org.bukkit.event.entity.EntityDamageEvent.DamageCause.ENTITY_ATTACK, source,
+                    (Double) call.getArgument(0))); return null;
+            }).when(target).damage(anyDouble(), any(org.bukkit.damage.DamageSource.class));
+            a.core.inventory.getInventory().setSelectedSlot(2);
+            f.dispatcher.accept(new io.papermc.paper.event.player.PrePlayerAttackEntityEvent(a.player, target, true));
+            PartyBookNativeTest.drain(f); PartyBookNativeTest.drain(f);
+            assertEquals(1, hits.get());
+            var storage = (games.dmg.fantasystick.persistence.CharacterStorage)
+                FantasyStickLifecycleNativeTest.Fixture.field(f.plugin, "characters");
+            var deadline = storage.find(a.core.record.id()).get().orElseThrow().cooldowns().get("great_sword");
+            assertNotNull(deadline);
+
+            a.core.inventory.getInventory().setSelectedSlot(0); PartyBookNativeTest.open(f, a);
+            var unlearn = abilityButton(a, "[Unlearn]", "great_sword");
+            PartyBookNativeTest.click(f, a, unlearn); PartyBookNativeTest.click(f, a, unlearn);
+            PartyBookNativeTest.drain(f); PartyBookNativeTest.drain(f);
+            var refunded = storage.find(a.core.record.id()).get().orElseThrow();
+            assertEquals(BigInteger.valueOf(40), refunded.unspentPoints());
+            assertFalse(refunded.learned().contains("great_sword"));
+            assertTrue(refunded.loadout().stream().noneMatch("great_sword"::equals));
+            assertEquals(deadline, refunded.cooldowns().get("great_sword"));
+            assertTrue(new games.dmg.fantasystick.items.SessionControls(
+                (games.dmg.fantasystick.ability.AbilityRegistry) FantasyStickLifecycleNativeTest.Fixture.field(f.plugin, "abilityRegistry"))
+                .ability(a.core.inventory.getItem(2)).isEmpty());
+
+            learnAndAssign(f, a);
+            assertEquals(deadline, storage.find(a.core.record.id()).get().orElseThrow().cooldowns().get("great_sword"));
+            a.core.inventory.getInventory().setSelectedSlot(2);
+            f.dispatcher.accept(new io.papermc.paper.event.player.PrePlayerAttackEntityEvent(a.player, target, true));
+            PartyBookNativeTest.drain(f);
+            assertEquals(1, hits.get());
+            assertTrue(a.messages.stream().anyMatch(message -> message.contains("ready in")));
+
+            var sheet = a.core.inventory.getItemInOffHand().clone();
+            a.core.inventory.setItemInOffHand(null); f.changed(a); PartyBookNativeTest.drain(f); f.awaitCharacterAndReceipt(a);
+            var b = new FantasyStickLifecycleNativeTest.Actor(data); b.core.inventory.setItemInOffHand(sheet);
+            f.players.put(b.core.id, b.player); f.activate(b);
+            when(b.player.getAttackCooldown()).thenReturn(1.0f);
+            b.core.inventory.getInventory().setSelectedSlot(2);
+            f.dispatcher.accept(new io.papermc.paper.event.player.PrePlayerAttackEntityEvent(b.player, target, true));
+            PartyBookNativeTest.drain(f);
+            assertEquals(1, hits.get(), "Transfer cannot reset the character-bound recovery");
+            assertEquals(deadline, storage.find(a.core.record.id()).get().orElseThrow().cooldowns().get("great_sword"));
+        }
+    }
+
+    @Test void failedCooldownPersistenceDealsNoDamageOrFreeEffect() {
+        var storage = mock(games.dmg.fantasystick.persistence.CharacterStorage.class);
+        var sessions = mock(games.dmg.fantasystick.session.EquipmentSessions.class);
+        var parties = new games.dmg.fantasystick.party.PartyRoster(java.time.Clock.systemUTC(), ignored -> true);
+        var registry = new games.dmg.fantasystick.ability.AbilityRegistry();
+        var sword = new games.dmg.fantasystick.ability.GreatSword(
+            games.dmg.fantasystick.ability.GreatSword.Settings.defaults());
+        registry.register(sword.definition());
+        var base = new games.dmg.fantasystick.crafting.CharacterFactory().create(
+            games.dmg.fantasystick.progression.ProgressionRules.defaults());
+        var stats = new java.util.EnumMap<>(base.stats());
+        stats.put(games.dmg.fantasystick.progression.Stat.STR, BigInteger.valueOf(12));
+        var record = new games.dmg.fantasystick.persistence.CharacterRecord(base.id(), base.name(), base.revision(), stats,
+            base.level(), base.experience(), base.unspentPoints(), base.health(), java.util.Set.of("great_sword"),
+            java.util.List.of("great_sword", "", "", "", "", "", ""), base.cooldowns(), base.restrictedKills(),
+            false, null, null);
+        var active = new games.dmg.fantasystick.session.EquipmentSessions.Active(java.util.UUID.randomUUID(),
+            java.util.UUID.randomUUID(), record.id());
+        var player = mock(org.bukkit.entity.Player.class);
+        var target = mock(org.bukkit.entity.LivingEntity.class);
+        when(target.getUniqueId()).thenReturn(java.util.UUID.randomUUID());
+        when(sessions.current(active)).thenReturn(true);
+        when(sessions.currentRecord(active)).thenReturn(java.util.Optional.of(record));
+        var failed = new java.util.concurrent.CompletableFuture<games.dmg.fantasystick.persistence.CharacterStorage.AbilityMutation>();
+        failed.completeExceptionally(new java.io.IOException("simulated Great Sword cooldown failure"));
+        when(storage.commitAbilityCooldown(eq(record.id()), eq(record.revision()), eq("great_sword"), any()))
+            .thenReturn(failed);
+        var failures = new java.util.ArrayList<games.dmg.fantasystick.ability.AbilityEngine.Failure>();
+        var engine = new games.dmg.fantasystick.ability.AbilityEngine(registry, storage, sessions, parties,
+            java.time.Clock.systemUTC(), Runnable::run, (delay, action) -> () -> {}, ignored -> {}, failures::add);
+        engine.accept(new games.dmg.fantasystick.session.ControlInput(player, active, 2, "great_sword",
+            games.dmg.fantasystick.session.ControlInput.Kind.ABILITY,
+            games.dmg.fantasystick.session.ControlInput.Gesture.ATTACK, target, 0, 1, () -> true));
+        verify(target, never()).damage(anyDouble(), any(org.bukkit.damage.DamageSource.class));
+        assertEquals(1, failures.size());
+        engine.close(); sword.close(); parties.close();
+    }
+
+    @Test void invalidGreatSwordBalanceFailsBeforeInstallingGameplay() throws Exception {
+        for (String configuration : java.util.List.of("great-sword-base-damage: -1\n",
+                "great-sword-recovery-seconds: -0.1\n", "great-sword-recovery-seconds: 31536001\n",
+                "great-sword-recovery-seconds: 0.0000000001\n", "great-sword-base-damage: nope\n")) {
+            var directory = data.resolve(Integer.toHexString(configuration.hashCode()));
+            java.nio.file.Files.createDirectories(directory);
+            java.nio.file.Files.writeString(directory.resolve("config.yml"), configuration);
+            try (var fixture = new FantasyStickLifecycleNativeTest.Fixture(directory)) {
+                assertThrows(IllegalArgumentException.class, () -> fixture.plugin.setEnabled(true));
+                assertTrue(fixture.order.isEmpty()); assertTrue(fixture.recipes.isEmpty());
+                assertFalse(java.nio.file.Files.exists(directory.resolve("characters")));
+            }
+        }
+    }
+
+    @Test void configuredDefinitionAndChargeCurvePreserveExactUncappedScaling() throws Exception {
+        java.nio.file.Files.writeString(data.resolve("config.yml"),
+            "great-sword-base-damage: 9\ngreat-sword-recovery-seconds: 2.5\n");
+        try (var f = new FantasyStickLifecycleNativeTest.Fixture(data)) {
+            f.plugin.setEnabled(true);
+            var registry = (games.dmg.fantasystick.ability.AbilityRegistry)
+                FantasyStickLifecycleNativeTest.Fixture.field(f.plugin, "abilityRegistry");
+            var definition = registry.find("great_sword").orElseThrow();
+            assertEquals(java.time.Duration.ofMillis(2500), definition.cooldown());
+            assertEquals(new java.math.BigDecimal("9"), definition.parameters().get("base-damage"));
+            assertEquals("Great Sword", definition.name());
+            assertEquals(org.bukkit.Material.WOODEN_SWORD, definition.icon());
+            assertEquals(java.util.Map.of(games.dmg.fantasystick.progression.Stat.STR, BigInteger.valueOf(12)),
+                definition.requirements());
+            assertEquals(games.dmg.fantasystick.session.ControlInput.Gesture.ATTACK, definition.gesture());
+            var unavailable = new FantasyStickLifecycleNativeTest.Actor(data);
+            f.players.put(unavailable.core.id, unavailable.player); f.activate(unavailable);
+            unavailable.core.inventory.getInventory().setSelectedSlot(0); PartyBookNativeTest.open(f, unavailable);
+            String text = PartyBookNativeTest.text(unavailable);
+            assertTrue(text.contains("Great Sword"));
+            assertTrue(text.replaceAll("\\s+", "").contains("Unavailable:requirements"), text);
+            assertThrows(AssertionError.class, () -> abilityButton(unavailable, "[Learn]", "great_sword"));
+        }
+        assertEquals(new java.math.BigDecimal("8"),
+            games.dmg.fantasystick.ability.GreatSword.damage(BigInteger.valueOf(12), 1.0f));
+        assertEquals(new java.math.BigDecimal("3.2"),
+            games.dmg.fantasystick.ability.GreatSword.damage(BigInteger.valueOf(12), 0.5f));
+        assertEquals(new java.math.BigDecimal("1.6"),
+            games.dmg.fantasystick.ability.GreatSword.damage(BigInteger.valueOf(12), 0.0f));
+        assertEquals(new java.math.BigDecimal(BigInteger.TEN.pow(500).subtract(BigInteger.TEN)
+            .divide(BigInteger.TWO).add(BigInteger.valueOf(7))),
+            games.dmg.fantasystick.ability.GreatSword.damage(BigInteger.TEN.pow(500), 1.0f));
+    }
+
+    private static void learnAndAssign(FantasyStickLifecycleNativeTest.Fixture fixture,
+                                       FantasyStickLifecycleNativeTest.Actor actor) throws Exception {
+        actor.core.inventory.getInventory().setSelectedSlot(0); PartyBookNativeTest.open(fixture, actor);
+        PartyBookNativeTest.click(fixture, actor, abilityButton(actor, "[Learn]", "great_sword"));
+        PartyBookNativeTest.drain(fixture); PartyBookNativeTest.drain(fixture);
+        PartyBookNativeTest.click(fixture, actor, abilityButton(actor, "[3]", "great_sword"));
+        PartyBookNativeTest.drain(fixture); PartyBookNativeTest.drain(fixture);
+    }
+
+    private static net.minecraft.network.chat.ClickEvent.Custom abilityButton(
+            FantasyStickLifecycleNativeTest.Actor actor, String label, String ability) {
+        var book = org.bukkit.craftbukkit.inventory.CraftItemStack.asNMSCopy(actor.books.getLast())
+            .get(net.minecraft.core.component.DataComponents.WRITTEN_BOOK_CONTENT);
+        assertNotNull(book);
+        for (var page : book.pages()) {
+            var found = abilityButton(page.raw(), label, ability);
+            if (found != null) return found;
+        }
+        throw new AssertionError("Missing " + label + " action for " + ability);
+    }
+
+    private static net.minecraft.network.chat.ClickEvent.Custom abilityButton(
+            net.minecraft.network.chat.Component component, String label, String ability) {
+        if (component.getString().equals(label)
+                && component.getStyle().getClickEvent() instanceof net.minecraft.network.chat.ClickEvent.Custom custom
+                && custom.payload().orElse(null) instanceof net.minecraft.nbt.StringTag payload
+                && payload.value().contains(":" + ability)) return custom;
+        for (var child : component.getSiblings()) {
+            var found = abilityButton(child, label, ability);
+            if (found != null) return found;
+        }
+        return null;
+    }
+
+    private static void withGreatSword(Path data, FantasyStickLifecycleNativeTest.Actor actor, int strength) throws Exception {
+        var repository = new games.dmg.fantasystick.persistence.YamlCharacterRepository(data);
+        var old = repository.load(actor.core.record.id()).orElseThrow();
+        var stats = new java.util.EnumMap<>(old.stats());
+        stats.put(games.dmg.fantasystick.progression.Stat.STR, BigInteger.valueOf(strength));
+        repository.replace(new games.dmg.fantasystick.persistence.CharacterRecord(old.id(), old.name(),
+            old.revision().add(BigInteger.ONE), stats, old.level(), old.experience(), old.unspentPoints(), old.health(),
+            java.util.Set.of("great_sword"), java.util.List.of("great_sword", "", "", "", "", "", ""),
+            old.cooldowns(), old.restrictedKills(), false, null, null), old.revision());
+    }
+
+    private static void withStrength(Path data, FantasyStickLifecycleNativeTest.Actor actor, int strength) throws Exception {
+        var repository = new games.dmg.fantasystick.persistence.YamlCharacterRepository(data);
+        var old = repository.load(actor.core.record.id()).orElseThrow();
+        var stats = new java.util.EnumMap<>(old.stats());
+        stats.put(games.dmg.fantasystick.progression.Stat.STR, BigInteger.valueOf(strength));
+        repository.replace(new games.dmg.fantasystick.persistence.CharacterRecord(old.id(), old.name(),
+            old.revision().add(BigInteger.ONE), stats, old.level(), old.experience(), old.unspentPoints(), old.health(),
+            old.learned(), old.loadout(), old.cooldowns(), old.restrictedKills(), false, null, null), old.revision());
+    }
+}

src/test/java/games/dmg/fantasystick/DistributionTest.java

@@ -42,6 +42,14 @@ class DistributionTest {
             assertTrue(defaults.contains("character-swap-cooldown-seconds: 900"),
                 "The delivered configuration must expose the reviewed 15-minute default");
             assertTrue(defaults.contains("adventure-mode: true"));
+            assertTrue(defaults.contains("great-sword-base-damage: 7"));
+            assertTrue(defaults.contains("great-sword-recovery-seconds: 1.2"));
+            for (String setting : java.util.List.of("frost-shard-base-damage: 4",
+                    "frost-shard-cooldown-seconds: 5", "frost-shard-range-blocks: 32",
+                    "frost-shard-lifetime-seconds: 5", "frost-shard-projectile-speed-blocks-per-tick: 1",
+                    "frost-shard-slowness-amplifier: 0", "frost-shard-slowness-duration-seconds: 2")) {
+                assertTrue(defaults.contains(setting), "Missing packaged Frost Shard default: " + setting);
+            }
             assertTrue(JavaPlugin.class.isAssignableFrom(FantasyStickPlugin.class));
             var entrypoint = jar.getJarEntry(metadata.getMain().replace('.', '/') + ".class");
             assertNotNull(entrypoint);

src/test/java/games/dmg/fantasystick/persistence/FrostShardSettingsTest.java

@@ -0,0 +1,100 @@
+package games.dmg.fantasystick.persistence;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.StandardCopyOption;
+import java.util.LinkedHashMap;
+import java.util.Map;
+import java.util.concurrent.TimeUnit;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.io.TempDir;
+
+class FrostShardSettingsTest {
+    @TempDir Path data;
+
+    @Test void serializesConcurrentAcceptedKeysWithoutLosingUnrelatedConfiguration() throws Exception {
+        Files.writeString(data.resolve("config.yml"), "adventure-mode: true\nunrelated: retained\n");
+        try (var settings = new FrostShardSettings(data, defaults())) {
+            var damage = settings.set(FrostShardSettings.BASE_DAMAGE, "9").toCompletableFuture();
+            var range = settings.set(FrostShardSettings.RANGE, "40.5").toCompletableFuture();
+            var savedDamage = damage.get(5, TimeUnit.SECONDS);
+            var savedRange = range.get(5, TimeUnit.SECONDS);
+            assertEquals("9", savedDamage.value()); assertEquals("40.5", savedRange.value());
+            assertEquals(new java.math.BigInteger("4"), settings.settings().baseDamage(),
+                "Durability acknowledgment alone must not publish runtime settings");
+            settings.publish(savedRange); settings.publish(savedDamage); // stale callback cannot roll back the newer snapshot.
+            assertEquals(new java.math.BigInteger("9"), settings.settings().baseDamage());
+            assertEquals(40.5, settings.settings().range());
+            var saved = (Map<?, ?>) new org.yaml.snakeyaml.Yaml().load(Files.readString(data.resolve("config.yml")));
+            assertEquals(Boolean.TRUE, saved.get("adventure-mode"));
+            assertEquals("retained", saved.get("unrelated"));
+            assertEquals("9", String.valueOf(saved.get(FrostShardSettings.BASE_DAMAGE)));
+            assertEquals("40.5", String.valueOf(saved.get(FrostShardSettings.RANGE)));
+        }
+    }
+
+    @Test void rejectsMalformedAndOutOfRangeValuesBeforeQueueingOrChangingEffectiveState() {
+        try (var settings = new FrostShardSettings(data, defaults())) {
+            for (var entry : Map.of(
+                    FrostShardSettings.BASE_DAMAGE, "-1",
+                    FrostShardSettings.COOLDOWN, "31536001",
+                    FrostShardSettings.RANGE, "0",
+                    FrostShardSettings.LIFETIME, "0",
+                    FrostShardSettings.SPEED, "Infinity",
+                    FrostShardSettings.AMPLIFIER, "256",
+                    FrostShardSettings.SLOWNESS, "0").entrySet()) {
+                assertThrows(IllegalArgumentException.class, () -> settings.set(entry.getKey(), entry.getValue()));
+            }
+            assertThrows(IllegalArgumentException.class, () -> settings.set(FrostShardSettings.BASE_DAMAGE, "1.5"));
+            assertThrows(IllegalArgumentException.class, () -> settings.set(FrostShardSettings.COOLDOWN, "0.0000000001"));
+            assertEquals("4", settings.value(FrostShardSettings.BASE_DAMAGE));
+            assertFalse(Files.exists(data.resolve("config.yml")));
+        }
+    }
+
+    @Test void failedAtomicReplacementRetainsEffectiveAndFileStateAndAllowsOneExplicitRetry() throws Exception {
+        Files.writeString(data.resolve("config.yml"), "frost-shard-base-damage: 4\n");
+        var fail = new java.util.concurrent.atomic.AtomicBoolean(true);
+        try (var settings = new FrostShardSettings(data, defaults(), (from, to) -> {
+            if (fail.getAndSet(false)) throw new java.io.IOException("simulated replacement failure");
+            Files.move(from, to, StandardCopyOption.REPLACE_EXISTING);
+        })) {
+            assertThrows(java.util.concurrent.ExecutionException.class, () ->
+                settings.set(FrostShardSettings.BASE_DAMAGE, "9").toCompletableFuture().get(5, TimeUnit.SECONDS));
+            assertEquals("4", settings.value(FrostShardSettings.BASE_DAMAGE));
+            assertTrue(Files.readString(data.resolve("config.yml")).contains("4"));
+            var retry = settings.set(FrostShardSettings.BASE_DAMAGE, "9").toCompletableFuture()
+                .get(5, TimeUnit.SECONDS);
+            assertEquals("9", retry.value());
+            assertEquals("4", settings.value(FrostShardSettings.BASE_DAMAGE));
+            settings.publish(retry);
+            assertEquals("9", settings.value(FrostShardSettings.BASE_DAMAGE));
+        }
+    }
+
+    @Test void rejectsUnsafeConfigurationAndLockFilesAndPostCloseWrites() throws Exception {
+        if (!System.getProperty("os.name", "").toLowerCase().contains("win")) {
+            var external = data.resolveSibling(data.getFileName() + "-outside");
+            Files.writeString(external, "safe\n");
+            Files.createSymbolicLink(data.resolve("config.yml"), external);
+            try (var settings = new FrostShardSettings(data, defaults())) {
+                assertThrows(java.util.concurrent.ExecutionException.class, () ->
+                    settings.set(FrostShardSettings.BASE_DAMAGE, "9").toCompletableFuture().get(5, TimeUnit.SECONDS));
+                assertEquals("safe\n", Files.readString(external));
+            }
+            Files.delete(data.resolve("config.yml")); Files.deleteIfExists(external);
+        }
+        var settings = new FrostShardSettings(data, defaults()); settings.close();
+        assertThrows(java.util.concurrent.ExecutionException.class, () ->
+            settings.set(FrostShardSettings.BASE_DAMAGE, "9").toCompletableFuture().get(5, TimeUnit.SECONDS));
+        settings.drained().toCompletableFuture().get(5, TimeUnit.SECONDS);
+    }
+
+    private static Map<String, String> defaults() {
+        var result = new LinkedHashMap<String, String>();
+        for (String key : FrostShardSettings.keys()) result.put(key, FrostShardSettings.defaultValue(key));
+        return result;
+    }
+}