The Reputation System in Genshin Impact allows players to earn rewards by exploring a region and completing quests there. Now that Sumeru has been released with Genshin Impact 3.0, players have access to an entirely new region with it's own new Reputation System, which means players also have access to a bunch of new rewards for completing quests.
Here's how to unlock the Reputation System in Sumeru.
How to Unlock the Sumeru Reputation System in Genshin Impact
Once players get to Sumeru, the first thing players will need to do is complete the "Chapter 3 - Act 2: The Morn a Thousand Roses Brings" Archon Quest that was added in the new update. To do so, players have to be at least Adventure Rank 35, and have completed the "Chapter 2 - Act 4: Requiem of the Echoing Depths" Archon Quest already.
Once the "Morn of a Thousand Roses Brings" quest is complete, players should go to talk to Katheryne in Sumeru City. From here, players will unlock the "Corps of Thirty Recruitment" World Quest. To complete this quest, players need to go to the NPC Effendi, who is in he northeast corner of Sumeru City, north of the spiral steps (the NPC will be indicated by a marker on the map when this quest is active).
Once players complete all the steps of the "Corps of Thirty Recruitment" quest and talk to Effendi, the Sumeru Reputation System, as well as all it's quests and rewards, will be unlocked.