More details will be added as they come, was just announced at the Reaper of Souls launch party.

A tiered rift system that becomes increasingly difficult as you advance. An "endless dungeon" of sorts. Chance at receiving a "greater rift key" when completing a normal rift.

Finishing a greater rift unlocks an even harder rift. Clearing that rift unlocks another, so on and so on.

Play and complete harder and harder rifts until you fail.

Your progress will be ranked on a leader board