This Warhammer 3 mod lets you play a non-campaign sandbox

pcgamesn.com:

As we all suspected he would, PCGamesN editor Rich really likes Total War: Warhammer III, the capstone in the fantasy strategy game trilogy from Creative Assembly. The one minor complaint in his Total War: Warhammer III review is that the Chaos Rift system often clashes with the rest of the campaign. If you’ve been frustrated by this too, we have good news: there’s now a way to turn it off.

The Chaos Realm Toggle mod by DrunkFlamingo adds a tick box for when you begin a new game in Total War: Warhammer III. By default, it’s checked, which keeps the Chaos Realms storyline active. But if you untick the box, that gets disabled, and the rifts to the Chaos Realms will never open.

That will leave you free to putter about, building up armies and kingdoms as you might in Total War: Warhammer III’s Mortal Empires mode, when that arrives – only without the addition of the merged campaign map and the factions from the previous two games in the series. You won’t be racing your best army toward a tear in the fabric of space and time every 25 turns to do battle with some chaos god’s latest collection of frighteners.

This video by the Great Book of Grudges explains how you can get your hands on the latest version of the mod:

While you’ll have to join a Discord server and do a bit of scouting around on there to find it, once you’ve got the mod downloaded it’s a very simple thing to get set up – you just have to drop the file into your Warhammer 3 data folder.

The mod won’t affect existing saves, and if you remove the file while in the middle of a campaign, the Chaos Realms will simply turn back on. However, you’ll have to keep an eye out for any updates to the core game, because these may alter its functionality. But bear in mind that