feat(vigilante): add followers and combat scaling

design/log.md

@@ -6,6 +6,17 @@ description: Chronological record of material decisions affecting the Spigot Tyr
 
 # Spigot Tyrant Design Log
 
+## 2026-08-14 — Vigilante and Followers completed
+
+- Completed US-008 with `/vigilante` invitation, acceptance, dismissal, and leave flows while preserving independent Tyrant-side class assignments.
+- Added Tyrant/Vigilante combat tracking and continuously refreshed Strength and Resistance based on living same-world Followers within the configurable 50-block range, capped at Strength V and Resistance IV by default.
+- Every Vigilante death now awards progression only to the Tyrant killer, clears Followers, and applies normal recently-active replacement with previous-holder fallback.
+- Verified membership, dual alignment, scaling and caps, role maintenance, command metadata, and death/progression components with the Gradle suite.
+
+## 2026-08-14 — Vigilante and Follower implementation started
+
+- US-008 begins with test-first invitation membership, death reroll and Tyrant reward integration, combat tracking, and proximity-scaled capped effects.
+
 ## 2026-08-14 — Participation completed
 
 - Completed US-011 with `/tyrant status`, `optout`, `optin`, and confirmed `relinquish` flows plus comprehensive join messages for lifecycle, roles, classes, abilities, and cooldowns.

design/user-stories/us-008-support-vigilante-and-followers.md

@@ -2,7 +2,7 @@
 type: User Story
 title: "US-008: Support the Vigilante and Followers"
 description: Give the Vigilante a replaceable role and combat strength derived from nearby Followers.
-status: backlog
+status: done
 ---
 
 # US-008: Support the Vigilante and Followers
@@ -11,18 +11,18 @@ As the **Vigilante**, I want nearby living Followers to strengthen me against th
 
 ## Acceptance criteria
 
-- [ ] Exactly one active Vigilante exists while the game is running whenever an eligible player is available.
+- [x] Exactly one active Vigilante exists while the game is running whenever an eligible player is available.
-- [ ] The Vigilante can invite eligible opted-in players to become Followers, and recruitment requires acceptance.
+- [x] The Vigilante can invite eligible opted-in players to become Followers, and recruitment requires acceptance.
-- [ ] The Vigilante can dismiss Followers and Followers can leave voluntarily.
+- [x] The Vigilante can dismiss Followers and Followers can leave voluntarily.
-- [ ] While actively fighting the Tyrant, the Vigilante gains one potion level each of Strength and Resistance per living Follower in the same world within 50 blocks.
+- [x] While actively fighting the Tyrant, the Vigilante gains one potion level each of Strength and Resistance per living Follower in the same world within 50 blocks.
-- [ ] Offline, dead, opted-out, dismissed, or out-of-range Followers do not count.
+- [x] Offline, dead, opted-out, dismissed, or out-of-range Followers do not count.
-- [ ] A Vigilante or Follower may simultaneously hold one Tyrant-side class without losing Vigilante-side membership.
+- [x] A Vigilante or Follower may simultaneously hold one Tyrant-side class without losing Vigilante-side membership.
-- [ ] Effect levels update promptly as combat starts or ends and as Followers move, die, respawn, disconnect, or change assignment.
+- [x] Effect levels update promptly as combat starts or ends and as Followers move, die, respawn, disconnect, or change assignment.
-- [ ] Scaling is capped by validated configuration, defaulting to Strength V and Resistance IV.
+- [x] Scaling is capped by validated configuration, defaulting to Strength V and Resistance IV.
-- [ ] Every Vigilante death ends the assignment and triggers random replacement regardless of cause.
+- [x] Every Vigilante death ends the assignment and triggers random replacement regardless of cause.
-- [ ] The deceased Vigilante is excluded when another eligible non-Tyrant candidate exists and is reused only when no such candidate exists.
+- [x] The deceased Vigilante is excluded when another eligible non-Tyrant candidate exists and is reused only when no such candidate exists.
-- [ ] Followers are cleared rather than transferred when their Vigilante dies or loses the position.
+- [x] Followers are cleared rather than transferred when their Vigilante dies or loses the position.
-- [ ] The Tyrant is never eligible to be selected as Vigilante.
+- [x] The Tyrant is never eligible to be selected as Vigilante.
 
 ## Related
 

src/main/java/games/dmg/spigottyrant/FollowerResult.java

@@ -0,0 +1,10 @@
+package games.dmg.spigottyrant;
+
+import java.util.Map;
+import java.util.UUID;
+
+public record FollowerResult(Map<UUID, PlayerState> players, FollowerStatus status) {
+    public FollowerResult {
+        players = Map.copyOf(players);
+    }
+}

src/main/java/games/dmg/spigottyrant/FollowerService.java

@@ -0,0 +1,111 @@
+package games.dmg.spigottyrant;
+
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Optional;
+import java.util.UUID;
+
+public final class FollowerService {
+    private final Map<UUID, UUID> invitations = new HashMap<>();
+
+    public FollowerResult invite(
+        GameState game,
+        Map<UUID, PlayerState> players,
+        UUID vigilanteId,
+        UUID targetId
+    ) {
+        if (game.lifecycle() != GameLifecycle.RUNNING) {
+            return result(players, FollowerStatus.GAME_NOT_RUNNING);
+        }
+        if (game.vigilanteId().filter(vigilanteId::equals).isEmpty()) {
+            return result(players, FollowerStatus.NOT_VIGILANTE);
+        }
+        PlayerState target = players.get(targetId);
+        if (target == null || target.optedOutUntil().isPresent()
+                || game.tyrantId().filter(targetId::equals).isPresent()
+                || game.vigilanteId().filter(targetId::equals).isPresent()) {
+            return result(players, FollowerStatus.INELIGIBLE);
+        }
+        invitations.put(targetId, vigilanteId);
+        return result(players, FollowerStatus.INVITED);
+    }
+
+    public FollowerResult accept(
+        GameState game,
+        Map<UUID, PlayerState> players,
+        UUID targetId
+    ) {
+        UUID invitedBy = invitations.get(targetId);
+        if (invitedBy == null
+                || game.vigilanteId().filter(invitedBy::equals).isEmpty()) {
+            return result(players, FollowerStatus.NO_INVITATION);
+        }
+        PlayerState target = players.get(targetId);
+        if (target == null || target.optedOutUntil().isPresent()) {
+            invitations.remove(targetId);
+            return result(players, FollowerStatus.INELIGIBLE);
+        }
+        invitations.remove(targetId);
+        return updated(players, withFollower(target, Optional.of(invitedBy)), FollowerStatus.JOINED);
+    }
+
+    public FollowerResult dismiss(
+        GameState game,
+        Map<UUID, PlayerState> players,
+        UUID vigilanteId,
+        UUID targetId
+    ) {
+        if (game.vigilanteId().filter(vigilanteId::equals).isEmpty()) {
+            return result(players, FollowerStatus.NOT_VIGILANTE);
+        }
+        PlayerState target = players.get(targetId);
+        if (target == null || target.followerOf().filter(vigilanteId::equals).isEmpty()) {
+            return result(players, FollowerStatus.NOT_FOLLOWER);
+        }
+        return updated(players, withFollower(target, Optional.empty()), FollowerStatus.DISMISSED);
+    }
+
+    public FollowerResult leave(
+        GameState game,
+        Map<UUID, PlayerState> players,
+        UUID targetId
+    ) {
+        PlayerState target = players.get(targetId);
+        if (target == null || target.followerOf().isEmpty()) {
+            return result(players, FollowerStatus.NOT_FOLLOWER);
+        }
+        return updated(players, withFollower(target, Optional.empty()), FollowerStatus.LEFT);
+    }
+
+    public void clearInvitations() {
+        invitations.clear();
+    }
+
+    private static FollowerResult updated(
+        Map<UUID, PlayerState> players,
+        PlayerState updated,
+        FollowerStatus status
+    ) {
+        Map<UUID, PlayerState> replacement = new HashMap<>(players);
+        replacement.put(updated.playerId(), updated);
+        return result(replacement, status);
+    }
+
+    private static FollowerResult result(
+        Map<UUID, PlayerState> players,
+        FollowerStatus status
+    ) {
+        return new FollowerResult(players, status);
+    }
+
+    private static PlayerState withFollower(
+        PlayerState player,
+        Optional<UUID> followerOf
+    ) {
+        return new PlayerState(
+            player.playerId(), player.latestName(), player.lastLogin(), player.optedOutUntil(),
+            player.tyrantClass(), followerOf, player.cooldownEnds(),
+            player.readyAbilityItems(), player.capturedMobs()
+        );
+    }
+}

src/main/java/games/dmg/spigottyrant/FollowerStatus.java

@@ -0,0 +1,13 @@
+package games.dmg.spigottyrant;
+
+public enum FollowerStatus {
+    INVITED,
+    JOINED,
+    DISMISSED,
+    LEFT,
+    GAME_NOT_RUNNING,
+    NOT_VIGILANTE,
+    INELIGIBLE,
+    NO_INVITATION,
+    NOT_FOLLOWER
+}

src/main/java/games/dmg/spigottyrant/PluginSettings.java

@@ -28,6 +28,7 @@ public record PluginSettings(
     int fixerStrengthLevel,
     int fixerNormalHeartRows,
     int fixerNearTyrantHeartRows,
+    Duration vigilanteCombatDuration,
     Duration rosterIntelligenceCooldown,
     int tyrantStrengthLevel,
     int tyrantResistanceLevel,
@@ -65,6 +66,7 @@ public record PluginSettings(
                 "fixer-near-tyrant-heart-rows must be at least fixer-normal-heart-rows"
             );
         }
+        requirePositive(vigilanteCombatDuration, "vigilante-combat-seconds");
         requirePositive(rosterIntelligenceCooldown, "roster-intelligence-cooldown-seconds");
         requireEffectLevel(tyrantStrengthLevel, "tyrant-strength-level");
         requireEffectLevel(tyrantResistanceLevel, "tyrant-resistance-level");
@@ -99,6 +101,7 @@ public record PluginSettings(
             integer(values, "fixer-strength-level", 1),
             integer(values, "fixer-normal-heart-rows", 2),
             integer(values, "fixer-near-tyrant-heart-rows", 3),
+            duration(values, "vigilante-combat-seconds", Duration.ofSeconds(15)),
             duration(values, "roster-intelligence-cooldown-seconds", Duration.ofHours(24)),
             integer(values, "tyrant-strength-level", 1),
             integer(values, "tyrant-resistance-level", 1),

src/main/java/games/dmg/spigottyrant/SpigotTyrantPlugin.java

@@ -11,6 +11,7 @@ public final class SpigotTyrantPlugin extends JavaPlugin {
     private PluginSettings settings;
     private TyrantStateManager stateManager;
     private TyrantPresentation tyrantPresentation;
+    private VigilanteEffectController vigilanteEffects;
 
     @Override
     public void onEnable() {
@@ -46,6 +47,11 @@ public final class SpigotTyrantPlugin extends JavaPlugin {
             random
         );
         BukkitOnlinePlayerDirectory onlinePlayers = new BukkitOnlinePlayerDirectory();
+        FollowerService followers = new FollowerService();
+        VigilanteCombatTracker combatTracker = new VigilanteCombatTracker();
+        vigilanteEffects = new VigilanteEffectController(
+            stateManager, getServer(), combatTracker, settings, clock
+        );
         tyrantPresentation = new BukkitTyrantPresentation(getServer());
         ManagedRoleEffects managedEffects = new BukkitManagedRoleEffects(
             stateManager, tyrantPresentation
@@ -62,6 +68,8 @@ public final class SpigotTyrantPlugin extends JavaPlugin {
                 new RoleRelinquishmentService(succession, maintenance),
                 tyrantPresentation
             ));
+        Objects.requireNonNull(getCommand("vigilante"), "Missing vigilante metadata")
+            .setExecutor(new VigilanteCommand(stateManager, followers, onlinePlayers));
         Objects.requireNonNull(getCommand("tyrantadmin"), "Missing tyrantadmin metadata")
             .setExecutor(new TyrantAdminCommand(
                 stateManager,
@@ -84,6 +92,19 @@ public final class SpigotTyrantPlugin extends JavaPlugin {
             ),
             this
         );
+        getServer().getPluginManager().registerEvents(
+            new VigilanteDeathListener(
+                stateManager, new TyrantProgressionService(), maintenance,
+                getServer(), clock
+            ),
+            this
+        );
+        getServer().getPluginManager().registerEvents(
+            new VigilanteCombatListener(
+                stateManager, combatTracker, clock, settings.vigilanteCombatDuration()
+            ),
+            this
+        );
         long maintenanceTicks = Math.max(
             1L, Math.multiplyExact(settings.selectionRetryInterval().toSeconds(), 20L)
         );
@@ -95,12 +116,16 @@ public final class SpigotTyrantPlugin extends JavaPlugin {
             maintenanceTicks,
             maintenanceTicks
         );
+        getServer().getScheduler().runTaskTimer(this, vigilanteEffects, 10L, 10L);
         getServer().getScheduler().runTaskTimer(this, stateManager::saveIfDirty, 600L, 600L);
         getLogger().info("Spigot Tyrant enabled.");
     }
 
     @Override
     public void onDisable() {
+        if (vigilanteEffects != null) {
+            vigilanteEffects.clear();
+        }
         if (tyrantPresentation != null) {
             tyrantPresentation.clear();
         }

src/main/java/games/dmg/spigottyrant/VigilanteCombatListener.java

@@ -0,0 +1,50 @@
+package games.dmg.spigottyrant;
+
+import java.time.Clock;
+import java.time.Duration;
+import java.util.UUID;
+import org.bukkit.entity.Player;
+import org.bukkit.event.EventHandler;
+import org.bukkit.event.EventPriority;
+import org.bukkit.event.Listener;
+import org.bukkit.event.entity.EntityDamageByEntityEvent;
+
+public final class VigilanteCombatListener implements Listener {
+    private final TyrantStateManager stateManager;
+    private final VigilanteCombatTracker tracker;
+    private final Clock clock;
+    private final Duration combatDuration;
+
+    public VigilanteCombatListener(
+        TyrantStateManager stateManager,
+        VigilanteCombatTracker tracker,
+        Clock clock,
+        Duration combatDuration
+    ) {
+        this.stateManager = stateManager;
+        this.tracker = tracker;
+        this.clock = clock;
+        this.combatDuration = combatDuration;
+    }
+
+    @EventHandler(priority = EventPriority.MONITOR, ignoreCancelled = true)
+    public void onDamage(EntityDamageByEntityEvent event) {
+        if (!(event.getEntity() instanceof Player damaged)
+                || !(event.getDamager() instanceof Player attacker)) {
+            return;
+        }
+        GameState game = stateManager.game();
+        if (game.lifecycle() != GameLifecycle.RUNNING
+                || game.tyrantId().isEmpty() || game.vigilanteId().isEmpty()) {
+            return;
+        }
+        UUID first = damaged.getUniqueId();
+        UUID second = attacker.getUniqueId();
+        UUID tyrant = game.tyrantId().orElseThrow();
+        UUID vigilante = game.vigilanteId().orElseThrow();
+        if ((first.equals(tyrant) && second.equals(vigilante))
+                || (first.equals(vigilante) && second.equals(tyrant))) {
+            tracker.markCombat(clock.instant(), combatDuration);
+        }
+    }
+}

src/main/java/games/dmg/spigottyrant/VigilanteCombatTracker.java

@@ -0,0 +1,21 @@
+package games.dmg.spigottyrant;
+
+import java.time.Duration;
+import java.time.Instant;
+import java.util.Optional;
+
+public final class VigilanteCombatTracker {
+    private Optional<Instant> activeUntil = Optional.empty();
+
+    public void markCombat(Instant now, Duration duration) {
+        activeUntil = Optional.of(now.plus(duration));
+    }
+
+    public boolean isActive(Instant now) {
+        return activeUntil.filter(deadline -> deadline.isAfter(now)).isPresent();
+    }
+
+    public void clear() {
+        activeUntil = Optional.empty();
+    }
+}

src/main/java/games/dmg/spigottyrant/VigilanteCommand.java

@@ -0,0 +1,83 @@
+package games.dmg.spigottyrant;
+
+import java.util.Locale;
+import org.bukkit.ChatColor;
+import org.bukkit.command.Command;
+import org.bukkit.command.CommandExecutor;
+import org.bukkit.command.CommandSender;
+import org.bukkit.entity.Player;
+
+public final class VigilanteCommand implements CommandExecutor {
+    private final TyrantStateManager stateManager;
+    private final FollowerService followers;
+    private final OnlinePlayerDirectory onlinePlayers;
+
+    public VigilanteCommand(
+        TyrantStateManager stateManager,
+        FollowerService followers,
+        OnlinePlayerDirectory onlinePlayers
+    ) {
+        this.stateManager = stateManager;
+        this.followers = followers;
+        this.onlinePlayers = onlinePlayers;
+    }
+
+    @Override
+    public boolean onCommand(
+        CommandSender sender,
+        Command command,
+        String label,
+        String[] arguments
+    ) {
+        if (!(sender instanceof Player player)) {
+            sender.sendMessage("This command must be used by a player.");
+            return true;
+        }
+        FollowerResult result;
+        Player target = null;
+        if (arguments.length == 1 && arguments[0].equalsIgnoreCase("accept")) {
+            result = followers.accept(stateManager.game(), stateManager.players(),
+                player.getUniqueId());
+        } else if (arguments.length == 1 && arguments[0].equalsIgnoreCase("leave")) {
+            result = followers.leave(stateManager.game(), stateManager.players(),
+                player.getUniqueId());
+        } else if (arguments.length == 2
+                && (arguments[0].equalsIgnoreCase("invite")
+                    || arguments[0].equalsIgnoreCase("dismiss"))) {
+            target = onlinePlayers.findByName(arguments[1]);
+            if (target == null) {
+                player.sendMessage(ChatColor.RED + "That player must be online.");
+                return true;
+            }
+            stateManager.player(target.getUniqueId(), target.getName());
+            result = arguments[0].equalsIgnoreCase("invite")
+                ? followers.invite(
+                    stateManager.game(), stateManager.players(), player.getUniqueId(),
+                    target.getUniqueId()
+                )
+                : followers.dismiss(
+                    stateManager.game(), stateManager.players(), player.getUniqueId(),
+                    target.getUniqueId()
+                );
+        } else {
+            player.sendMessage(ChatColor.YELLOW
+                + "Usage: /vigilante <invite <player>|accept|dismiss <player>|leave>");
+            return true;
+        }
+        if (result.status() == FollowerStatus.JOINED
+                || result.status() == FollowerStatus.DISMISSED
+                || result.status() == FollowerStatus.LEFT) {
+            stateManager.replacePlayers(result.players());
+            stateManager.saveIfDirty();
+        }
+        player.sendMessage(ChatColor.YELLOW + "Follower action: "
+            + result.status().name().toLowerCase(Locale.ROOT).replace('_', ' ') + ".");
+        if (target != null && result.status() == FollowerStatus.INVITED) {
+            target.sendMessage(ChatColor.YELLOW + player.getName()
+                + " invited you to become a Follower. Use /vigilante accept.");
+        } else if (target != null && result.status() == FollowerStatus.DISMISSED) {
+            target.sendMessage(ChatColor.YELLOW + "You are no longer a Follower.");
+        }
+        return true;
+    }
+}

src/main/java/games/dmg/spigottyrant/VigilanteDeathListener.java

@@ -0,0 +1,62 @@
+package games.dmg.spigottyrant;
+
+import java.time.Clock;
+import java.util.Optional;
+import java.util.Set;
+import java.util.UUID;
+import org.bukkit.ChatColor;
+import org.bukkit.Server;
+import org.bukkit.entity.Player;
+import org.bukkit.event.EventHandler;
+import org.bukkit.event.EventPriority;
+import org.bukkit.event.Listener;
+import org.bukkit.event.entity.PlayerDeathEvent;
+
+public final class VigilanteDeathListener implements Listener {
+    private final TyrantStateManager stateManager;
+    private final TyrantProgressionService progression;
+    private final RoleMaintenanceService maintenance;
+    private final Server server;
+    private final Clock clock;
+
+    public VigilanteDeathListener(
+        TyrantStateManager stateManager,
+        TyrantProgressionService progression,
+        RoleMaintenanceService maintenance,
+        Server server,
+        Clock clock
+    ) {
+        this.stateManager = stateManager;
+        this.progression = progression;
+        this.maintenance = maintenance;
+        this.server = server;
+        this.clock = clock;
+    }
+
+    @EventHandler(priority = EventPriority.MONITOR)
+    public void onDeath(PlayerDeathEvent event) {
+        UUID victimId = event.getEntity().getUniqueId();
+        GameState game = stateManager.game();
+        if (game.lifecycle() != GameLifecycle.RUNNING
+                || game.vigilanteId().filter(victimId::equals).isEmpty()) {
+            return;
+        }
+        Optional<UUID> killerId = Optional.ofNullable(event.getEntity().getKiller())
+            .map(Player::getUniqueId);
+        GameState progressed = progression.recordVigilanteDeath(game, killerId);
+        PersistentState withProgress = new PersistentState(
+            progressed, stateManager.players()
+        );
+        Set<UUID> online = server.getOnlinePlayers().stream()
+            .map(Player::getUniqueId)
+            .collect(java.util.stream.Collectors.toUnmodifiableSet());
+        LifecycleState rerolled = maintenance.rerollVigilante(
+            withProgress, Optional.of(victimId), online, clock.instant()
+        );
+        stateManager.replaceState(rerolled);
+        stateManager.saveIfDirty();
+        String message = ChatColor.YELLOW + "The Vigilante died; a replacement "
+            + (rerolled.game().vigilanteId().isPresent() ? "has been selected." : "is pending.");
+        server.getOnlinePlayers().forEach(player -> player.sendMessage(message));
+    }
+}

src/main/java/games/dmg/spigottyrant/VigilanteEffectController.java

@@ -0,0 +1,98 @@
+package games.dmg.spigottyrant;
+
+import java.time.Clock;
+import java.util.Optional;
+import java.util.UUID;
+import org.bukkit.Server;
+import org.bukkit.entity.Player;
+import org.bukkit.potion.PotionEffect;
+import org.bukkit.potion.PotionEffectType;
+
+public final class VigilanteEffectController implements Runnable {
+    private static final int EFFECT_TICKS = 30;
+    private final TyrantStateManager stateManager;
+    private final Server server;
+    private final VigilanteCombatTracker tracker;
+    private final PluginSettings settings;
+    private final Clock clock;
+    private Optional<UUID> previousVigilante = Optional.empty();
+
+    public VigilanteEffectController(
+        TyrantStateManager stateManager,
+        Server server,
+        VigilanteCombatTracker tracker,
+        PluginSettings settings,
+        Clock clock
+    ) {
+        this.stateManager = stateManager;
+        this.server = server;
+        this.tracker = tracker;
+        this.settings = settings;
+        this.clock = clock;
+    }
+
+    @Override
+    public void run() {
+        GameState game = stateManager.game();
+        if (!previousVigilante.equals(game.vigilanteId())) {
+            previousVigilante.map(server::getPlayer).ifPresent(this::removeManagedEffects);
+            previousVigilante = game.vigilanteId();
+        }
+        Player vigilante = game.vigilanteId().map(server::getPlayer).orElse(null);
+        if (vigilante == null || game.lifecycle() != GameLifecycle.RUNNING
+                || !tracker.isActive(clock.instant()) || vigilante.isDead()) {
+            if (vigilante != null) {
+                removeManagedEffects(vigilante);
+            }
+            return;
+        }
+        int followers = nearbyLivingFollowers(game.vigilanteId().orElseThrow(), vigilante);
+        VigilantePower.Levels levels = VigilantePower.forFollowers(
+            followers, settings.followerStrengthCap(), settings.followerResistanceCap()
+        );
+        apply(vigilante, PotionEffectType.STRENGTH, levels.strength());
+        apply(vigilante, PotionEffectType.RESISTANCE, levels.resistance());
+    }
+
+    public void clear() {
+        previousVigilante.map(server::getPlayer).ifPresent(this::removeManagedEffects);
+        previousVigilante = Optional.empty();
+        tracker.clear();
+    }
+
+    private int nearbyLivingFollowers(UUID vigilanteId, Player vigilante) {
+        int count = 0;
+        double rangeSquared = settings.followerRangeBlocks()
+            * settings.followerRangeBlocks();
+        for (PlayerState state : stateManager.players().values()) {
+            if (state.followerOf().filter(vigilanteId::equals).isEmpty()
+                    || state.optedOutUntil().isPresent()) {
+                continue;
+            }
+            Player follower = server.getPlayer(state.playerId());
+            if (follower == null || follower.isDead()
+                    || !follower.getWorld().equals(vigilante.getWorld())) {
+                continue;
+            }
+            if (follower.getLocation().distanceSquared(vigilante.getLocation()) <= rangeSquared) {
+                count++;
+            }
+        }
+        return count;
+    }
+
+    private static void apply(Player player, PotionEffectType type, int level) {
+        if (level == 0) {
+            player.removePotionEffect(type);
+            return;
+        }
+        player.addPotionEffect(new PotionEffect(
+            type, EFFECT_TICKS, level - 1, false, true, true
+        ));
+    }
+
+    private void removeManagedEffects(Player player) {
+        player.removePotionEffect(PotionEffectType.STRENGTH);
+        player.removePotionEffect(PotionEffectType.RESISTANCE);
+    }
+}

src/main/java/games/dmg/spigottyrant/VigilantePower.java

@@ -0,0 +1,23 @@
+package games.dmg.spigottyrant;
+
+public final class VigilantePower {
+    private VigilantePower() {
+    }
+
+    public static Levels forFollowers(
+        int followerCount,
+        int strengthCap,
+        int resistanceCap
+    ) {
+        if (followerCount < 0 || strengthCap < 1 || resistanceCap < 1) {
+            throw new IllegalArgumentException("follower count and caps are invalid");
+        }
+        return new Levels(
+            Math.min(followerCount, strengthCap),
+            Math.min(followerCount, resistanceCap)
+        );
+    }
+
+    public record Levels(int strength, int resistance) {
+    }
+}

src/main/resources/config.yml

@@ -40,6 +40,7 @@ denied-mob-types:
   - WITHER
 
 # Tyrant and Vigilante effects
+vigilante-combat-seconds: 15
 roster-intelligence-cooldown-seconds: 86400
 tyrant-strength-level: 1
 tyrant-resistance-level: 1

src/main/resources/plugin.yml

@@ -8,6 +8,9 @@ commands:
   tyrant:
     description: View and use Spigot Tyrant game features.
     usage: /tyrant <status|choices|buy|assign|optout|optin|relinquish confirm>
+  vigilante:
+    description: Manage Vigilante Followers.
+    usage: /vigilante <invite <player>|accept|dismiss <player>|leave>
   tyrantadmin:
     description: Administer the Spigot Tyrant game.
     usage: /tyrantadmin <status|start|pause|resume|reset confirm>

src/test/java/games/dmg/spigottyrant/FollowerServiceTest.java

@@ -0,0 +1,70 @@
+package games.dmg.spigottyrant;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import java.time.Duration;
+import java.util.Map;
+import java.util.Optional;
+import java.util.Set;
+import java.util.UUID;
+import org.junit.jupiter.api.Test;
+
+final class FollowerServiceTest {
+    private static final UUID TYRANT = UUID.fromString("11111111-1111-1111-1111-111111111111");
+    private static final UUID VIGILANTE = UUID.fromString("22222222-2222-2222-2222-222222222222");
+    private static final UUID FOLLOWER = UUID.fromString("33333333-3333-3333-3333-333333333333");
+    private final FollowerService service = new FollowerService();
+
+    @Test
+    void invitationRequiresAcceptanceAndPreservesTyrantClass() {
+        GameState game = game();
+        PlayerState target = new PlayerState(
+            FOLLOWER, "Follower", Optional.empty(), Optional.empty(), TyrantClass.FIXER,
+            Optional.empty(), Map.of(), Set.of(), java.util.List.of()
+        );
+        Map<UUID, PlayerState> players = Map.of(FOLLOWER, target);
+
+        FollowerResult invited = service.invite(game, players, VIGILANTE, FOLLOWER);
+        FollowerResult accepted = service.accept(game, invited.players(), FOLLOWER);
+
+        assertEquals(FollowerStatus.INVITED, invited.status());
+        assertEquals(Optional.empty(), invited.players().get(FOLLOWER).followerOf());
+        assertEquals(FollowerStatus.JOINED, accepted.status());
+        assertEquals(Optional.of(VIGILANTE), accepted.players().get(FOLLOWER).followerOf());
+        assertEquals(TyrantClass.FIXER, accepted.players().get(FOLLOWER).tyrantClass());
+    }
+
+    @Test
+    void vigilanteCanDismissAndFollowerCanLeave() {
+        GameState game = game();
+        PlayerState follower = withFollower(PlayerState.newPlayer(FOLLOWER, "Follower"));
+
+        FollowerResult dismissed = service.dismiss(
+            game, Map.of(FOLLOWER, follower), VIGILANTE, FOLLOWER
+        );
+        FollowerResult left = service.leave(
+            game, Map.of(FOLLOWER, follower), FOLLOWER
+        );
+
+        assertEquals(FollowerStatus.DISMISSED, dismissed.status());
+        assertEquals(Optional.empty(), dismissed.players().get(FOLLOWER).followerOf());
+        assertEquals(FollowerStatus.LEFT, left.status());
+        assertEquals(Optional.empty(), left.players().get(FOLLOWER).followerOf());
+    }
+
+    private static GameState game() {
+        return new GameState(
+            GameLifecycle.RUNNING, Optional.of(TYRANT), Optional.of(VIGILANTE),
+            Optional.empty(), Optional.empty(), Optional.empty(), Duration.ZERO,
+            0, 0, Set.of()
+        );
+    }
+
+    private static PlayerState withFollower(PlayerState player) {
+        return new PlayerState(
+            player.playerId(), player.latestName(), player.lastLogin(), player.optedOutUntil(),
+            player.tyrantClass(), Optional.of(VIGILANTE), player.cooldownEnds(),
+            player.readyAbilityItems(), player.capturedMobs()
+        );
+    }
+}

src/test/java/games/dmg/spigottyrant/PluginMetadataTest.java

@@ -24,6 +24,7 @@ final class PluginMetadataTest {
         assertNotNull(commands);
         assertNotNull(commands.get("tyrant"));
         assertNotNull(commands.get("tyrantadmin"));
+        assertNotNull(commands.get("vigilante"));
         Map<?, ?> permissions = (Map<?, ?>) plugin.get("permissions");
         assertNotNull(permissions);
         Map<?, ?> admin = (Map<?, ?>) permissions.get("spigottyrant.admin");

src/test/java/games/dmg/spigottyrant/VigilantePowerTest.java

@@ -0,0 +1,14 @@
+package games.dmg.spigottyrant;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import org.junit.jupiter.api.Test;
+
+final class VigilantePowerTest {
+    @Test
+    void oneLevelPerNearbyFollowerIsCappedSafely() {
+        assertEquals(new VigilantePower.Levels(3, 3), VigilantePower.forFollowers(3, 5, 4));
+        assertEquals(new VigilantePower.Levels(5, 4), VigilantePower.forFollowers(10, 5, 4));
+        assertEquals(new VigilantePower.Levels(0, 0), VigilantePower.forFollowers(0, 5, 4));
+    }
+}