All chests are filled with various items including Gold, Gems, and Cards, and other items.

[Chest Types]
The are 6 main chest types - Normal, Silver, Gold, Rare, Unique, and Epic.
Each chest type can further be divided into different grades in order of ascending value - Shining, Huge, and Superb.

Other than the chest types mentioned above, there are additional special chests that can be acquired through gameplay.

[Match Star Chests]
Can be unlocked when enough "Match Stars" are accumulated from winning 1vs1 Matches.
Upto 2 Match Star Chests can be unlocked within 8 hours.

[Battle Star Chests]
Can be unlocked when enough "Battle Stars" are accumulated from Battle Royale Matches.
You can earn more Battle Stars depending on your standing in Battle Royale matches (1st - 3 Stars, 2nd - 2 Stars, 3rd - 1 Star).
There are 4 types of Battle Star Chests (Beginner, Light, Super, Royal) one for each stage.
Upto 1 Battle Star Chest of each type can be unlocked within 8 hours.

[Seasonal Event Chests]
Can be unlocked when you've activated the Home Run Pass and acquired enough event coins to unlock the chest reward.
Each event chest is themed differently according to the appropriate season.