In Reaper of Souls, Split Bounty is something you should keep your eye on. With Split Farming, every player in your party gets a chance to get loot from Horadric Caches which seems like a good idea since you can get Horadric Caches specific Legendaries.
Check out our guide on Horadric Caches Only Legendaries for more details!
In addition to this, it also allows you to rack up XP fast, gain gems, Rift Key Fragments, and Blood Shards. For more help on Reaper of Souls, read our Legendary Items, Crusader Builds and Gold Farming Guide.
You can have any difficulty of your choice, but Torment I seem like an ideal setting since you will have better loot and much more XP. Although certain drops are also available on Normal difficulty, but to increase your chances, Torment I is recommended.
Also note that with 4 players, you will be fighting monsters with 4x hit-points so make sure you have necessary DPS and APS before jumping in.
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