Biome Chests

Biome Chests are Hardmode, post-Plantera Chests found within the Dungeon. Each contains one specific rare, powerful weapon, in addition to other miscellaneous items. While Biome Chests are placed during world creation, they are initially locked and can only be opened with an appropriate Biome Key, which will only become available in Hardmode, and only after Plantera has been defeated.

Only four Biome Chests (one of each type) will spawn in a particular world. Each represents a biome found in the current world. There are five types of Biome Chests in total, though a world will only contain one of the Crimson or Corruption variant, depending on which of those biomes the world contains.

To open a Biome Chest:


 * Kill Plantera.
 * Obtain the appropriate Biome Key by killing enemies within their respective biome.
 * Return to the Dungeon and find the appropriate Chest for the Key you found.

Types
The chests also contain common items depending on the height they were found:


 * Surface
 * Underground
 * Caverns

Tips

 * Biome Key drops are incredibly rare (1/2500 is the chance of a key dropping from a defeated enemy in a biome). You'll probably need to defeat many thousands: 1732 to have a 50% chance, 3000 for 70%, and 5750 for 90%. With the right equipment and some time, you can set up a mold farm or grinder in the biome to get there sooner.