All Chests contain rewards, which can include Rings, Red Star Rings and Runner Cards. The amount of rewards in each Chest depends on the type of Chest and the your current tier level.
Each chest takes a certain amount of time to unlock - once unlocked, you received the items it contains!
Battle Chests are awarded after each battle. There is a different Battle Chest for each finishing position, with first place containing the most rewards, and fourth place containing the least. A maximum of 25 Battle Chests can be earned each day.
Victory Chests are awarded for finishing first or second in a battle. A Victory Chest must be unlocked over a set time before it can be opened and only one Victory Chest can be set to unlock at any time. Victory Chests are usually Silver, but occasionally, a more valuable Chest will be rewarded instead.
Free Chests are automatically rewarded four hours after a previous one has been claimed. Up to two Free Chests can be held at once. They always contain Red Star Rings.