---
type: User Story
title: "US-019: Change a Pocket Base biome"
description: Let Pocket Base owners purchase biome changes that alter natural mob selection without changing their builds.
status: done
---

# US-019: Change a Pocket Base biome

As a **Pocket Base owner**, I want to change my Pocket Base biome so that I can control its biome-specific atmosphere and natural mob selection without rebuilding it.

## Acceptance criteria

- [x] A Pocket Base owner can use `/basesettings pocket type <void|nether|overworld> <subtype>` to select a compatible biome.
- [x] Void supports `the_void`; Nether supports its vanilla biome subtypes; and Overworld supports its vanilla biome subtypes.
- [x] New and previously unconfigured Pocket Bases default to the void type and `the_void` subtype.
- [x] Each change atomically charges a configurable currency and amount that default to 16 netherite blocks.
- [x] Selecting the active subtype or providing an invalid type/subtype combination is rejected without charging.
- [x] Changing subtypes within the same type incurs the configured cost.
- [x] The selected biome is applied across every unlocked Pocket Base column without changing blocks, entities, inventories, portals, level, or the mob-spawning preference.
- [x] Newly unlocked terrain receives the selected biome.
- [x] When natural mob spawning is enabled, Minecraft can use the selected biome for applicable natural mob selection.
- [x] The selected type and subtype persist through restarts and appear in `/basesettings status`.
- [x] The command, types, and compatible subtypes are offered through contextual autocomplete.
- [x] Failed biome application or persistence restores the prior biome and does not consume payment.

## Related

- [US-015: Unlock a Pocket Base](us-015-unlock-a-pocket-base.md)
- [US-017: Expand a Pocket Base](us-017-expand-a-pocket-base.md)
- [US-018: Control Pocket Base mob spawning](us-018-control-pocket-base-mob-spawning.md)