Daily Chests are reward chests that become available once per day. You can access the Daily Chest from the top right hand corner of the main screen, but you need rewards points in order to open them. After every battle in any Tournament, 3 points are collected for a win, and 1 point is collected for a loss, and a Daily Chest becomes available after 20 points have been collected. After you have collected a Daily Chest, you must wait a little while before another one becomes available.