how to find key´s

[kiNX]

I just defeated the dungeon boss, and several chests have appeared but I don't have the keys to open them... including the hell chests. Can anyone help me figure out how to at least get the keys to open the hell chests?

[Duchess Minty]

You need a shadow key to open the chests in the underworld, it's obtained randomly from one of the many gold chests in the dungeon. Keys for the gold chests can be obtained through killing the enemies in the dungeon or the large slimes that occasionally spawn.

[koimeiji]

There's three different types of locked chests.

Gold locked chests, found in the dungeon, require gold keys which are a rare drop from all the dungeon mobs, as well as a guaranteed drop from dungeon slimes. The keys are consumed on use.

Shadow locked chests, found in the underworld, require a shadow key. Shadow keys have a chance to be found in the locked gold chests, and I'm pretty sure it's guaranteed that at least one locked gold chest has one. Shadow keys aren't consumed on use; you can unlock all shadow chests with a single key.

Biome locked chests found primarily in the dungeon, meanwhile, require a biome key, which is a very rare drop from any mob once you reach Hardmode. The type of key that drops depends on what biome you're in. They also cannot be used until you defeat Plantera, a mid-Hardmode boss.