Treasure chest

Treasure chests, also named Chests, are a type of object in the Final Fantasy franchise. Most of them contain an item which is either common or valuable, and a handful contains some gil. Occasionally, the party stumbles upon a treasure chest with no contents. Some have a monster-in-a-box which must be defeated before the item can be obtained. Treasure chests first appear in the first game, Final Fantasy.

There are enemies named Mimics that heavily resemble treasure chests. At first, they disguise themselves as such, but if a character opens them, the Mimic reveals itself and attacks.

Final Fantasy Mystic Quest
In Final Fantasy Mystic Quest, treasure chests are brown and made of wood. They appear in most areas except the world map, and contain a common item such as potions or explosives. Whenever Benjamin exits back to the world map, the treasure chests' contents are reset; the player can strategically exploit this to have Benjamin obtain numerous items of a certain type until his inventory is full. There are also red treasure chests that contain either a key item or some other exclusive item such as a weapon, an armor, or a spellbook.