Unlike Diablo III, players cannot change the game difficulty in Diablo IV by going into the session’s menu. Instead, there is a new way that players can increase or decrease the difficulty of their game. Once you make it past the Prologue chapter, you will find yourself in Kyovashad. From there, you can walk directly north and make your way to a statue of Inarius. It is labeled as the World Tier Statue. Click on that statue to bring up the various tiers of difficulty options available in Diablo IV.
This statue can change the game difficulty of Diablo IV without you needing to create an entirely new session. However, harder difficulties do have certain conditions that need to be met in order to access them. This includes completing certain Dungeons tied to Story Quests on a specific difficulty. Increasing your difficulty will make the game harder by default, but will give players better rewards. This includes higher rarity gear drops, increased experience and difficulty, and other valuable items dropping.
However, please keep in mind that if you are in a party, all members will need to be in the city with the accompanying World Tier Statue in order for it to take affect. Also, if you change the difficulty of your game, all portals you may have opened to return to town will close. This means that if you are in dungeon and head back to change the difficulty, that portal will close.
Diablo IV will launch on June 6, 2023 for the PS4, PS5, Xbox One, Xbox Series X, and PC, and its Early Access beta weekend will be held March 17-20, 2023. The open beta will run March 24-27, 2023.