Diablo 3 Challenge Rifts are weekly activities that refresh on Monday at 1 pm Pacific Standard Time for NA and Tuesday at 4 am Central European Time for EU. They place the player into a pre-set dungeon with a pre-determined class, skill set and items selection that cannot be changed. You can move skills around to accommodate keybindings but other than that you’re at the mercy of the Challenge.
In addition to the weekly Leaderboard, completing a Challenge Rift rewards a Challenge Rift Cache if completed in the time limit. This Cache has quite the assortment of materials and a decent amount of them, doing this weekly throughout the Season is well worth the time it takes to complete. This Cache is also pivotal for a Season start as it can provide your level 1 character with a tremendous starting advantage. NEVER complete a Challenge Rift the week a Season is about to begin, if you wait until the season starts you can open the Cache on your brand new seasonal Character! Below are the materials you’ll receive when opening up your Cache:
A delay may occur in some cases such as but not limited to: start of a new season, tight or busy schedule and public holidays.