Your seasonal character, however, will be moved to the Eternal Realm at the end of the season, where it will remain playable. The season will introduce fresh questlines, separate from the campaign narrative, as well as new gameplay features that will change the experience of leveling and developing your new character - all of which will be exclusive to the season and will be retired at the end of the three months. You’ll need to complete the game’s campaign on one character before you can access it.

Seasons in Diablo 4 will be quarterly, with the first coming in “mid to late July” - a matter of weeks after the game’s launch on June 22. Oddly, Blizzard does not go out of its way to explain this, perhaps assuming that it will be taken as read by the Diablo community, but it has been confirmed in previous interviews.

The takeaway is that it all sounds pretty standard for a live service game, with one twist - there’s a heavy focus on seasonal content that, as per Diablo tradition, can only be accessed by starting a fresh seasonal character.

Blizzard has detailed its plans for the post-launch Diablo 4 experience in a fresh livestream and developer blog, focusing on seasons, battle passes (including pricing), and the shop.

Diablo 3 season 22 end