Key

The Key is a currency introduced in the 12.1.0 update.

Appearance
They are three golden keys, along with a smaller sized, possibly a mini-toy Pixel Gun, that are chained all together into a silver chain.

Spending
The keys can only be spent on opening Event Chests.

Obtaining
Keys are obtaining via victories in modes, such as Team Fight or Deathmatch. Usually, this is the amount of keys that you can earn in modes: Note: The unmentioned positions do not earn keys.
 * In Team Fight, Flag Capture and Point Capture:
 * The 1st place in the winning team earns 5 keys.
 * The 2nd place in the winning team earns 4 keys.
 * The 3rd place in the winning team earns 3 keys.
 * The 4th place in the winning team earns 2 keys.
 * The 5th place in the winning team earns 1 key.
 * In Deathmatch:
 * The 1st place earns 5 keys.
 * The 2nd place earns 4 keys.
 * The 3rd place earns 3 keys.
 * The 4th place earns 2 keys.
 * The 5th place earns 1 key.
 * In Deadly Games, Block Crash and Duel:
 * The winner earns 5 keys.
 * In Co-op Survival:
 * The 1st place earns 3 keys.
 * The 2nd place earns 2 keys.
 * The 3rd place earns 1 key.

Keys can also be obtained via spending gems.

Trivia

 * This is the 4th currency introduced into Pixel Gun 3D, the other 3 are coins, gems and tickets.
 * Its only use is to open Event Chests.
 * This and Tickets are currencies that can be bought with gems instead of microtransactions.