Greater Rifts are different from Nephalem Rifts in that there's a time limit to get a bonus Legendary Gem upgrade at the end, there are no loot or gold drops from mobs, and everything else dies once the Guardian appears.

You can adjust the difficulty of Greater Rifts independently from the rest of the game, and it's always a good idea to push harder, since clearing higher Greater Rift levels means more Blood Shard storage. Greater Rifts require keys, which you obtain from Horadric Caches (rewards for Bounties) and normal Nephalem Runs.

You still get loot and gold drops from foes, and you can continue to explore the rift even after the guardian is dead. You'll kill enemies to fill up the rift gauge, which then brings out the Rift Guardian when it's full. Nephalem Rifts don't require a key and are filled with enemy mobs. Because even if it's junk, you can salvage for crafting materials or sell for gold. You're going to find loot drops from enemy mobs, chests, objects, and other events throughout the game. Pick up everything that dropsĭiablo 3 is a game that's all about loot. When you reach Greater Rifts in the endgame content, you can change the difficulty of those runs independently from the rest of the current game. The only thing is that you can only go up or down one difficulty level, so if you want to go further than that, you'll need to quit the current game and change it from the main menu before starting. If it's too easy and not challenging at all, you can move it up. If you find it too hard, you can go lower. The great thing about Diablo 3 is the fact that you can change the difficulty at any time while you're playing too. But it's recommended to pick something a little higher because you get more experience and gold, so you'll level up faster. You may think about starting on Normal if you're new.

Diablo 3 class skills