Biome Keys are Hardmode items used to open Biome Chests. Though unusable until Plantera is defeated, they can be dropped at any time during Hardmode. On the Desktop version and Console version, each key has a 0.04% (1/2500) chance of dropping from an enemy in the key's respective biome. On the Old-gen console version, Mobile version, and version, they are not dropped directly and must be crafted from Biome Key Molds.
Any enemy in the biome that will drop coins when killed can drop the key, not just biome-exclusive enemies. Keys cannot be dropped by Meteor Heads (which don't drop coins in Hardmode), enemies spawned by a statue, Critters, or any enemy spawned by a pillar in the Lunar Events . Additionally, enemies in Hybrid Biomes have a chance to drop any key from its composite biomes. The biome is determined by which biome the player currently is in, not the enemy killed.
Any Biome Key dropped prior to defeating Plantera will display the tooltip "It has been cursed by a powerful Jungle creature" and will be unable to open its respective chest until Plantera is defeated. However, cursed keys are usable in worlds where Plantera has already been defeated. Biome Keys are consumed upon use.
- Desktop 126.96.36.199:
- No longer requires Key Molds; Biome Keys drop from enemies again.
- No longer drops from Meteor Heads.
- Can no longer open a Biome Chest until Plantera is defeated.
- Desktop 1.2.1: No longer drops from enemies, instead crafted with a mold dropped in the same way.