Total War: Warhammer 40,000 wants to be "the seminal Warhammer 40K game," says its devs, who sell me in just 8 words: "You can customize the fingers on Space Marines!" plus Gamestar article

Depending on how much time you've clocked in at the rumor mill, Total War: Warhammer 40,000 is either the worst-kept secret in gaming or one of 2025's most mind-blowing reveals. Either way, the news is out: here is a revolutionary step into sci-fi territory for Total War, taking the strategy series into the stars with a remarkably bold vision for capturing the vastness of 40K's setting.

While visiting Creative Assembly, Total War: Warhammer 40,000 is on the tip of every developer's tongue. Those on the technical side marvel at what the studio's new Warcore engine is already achieving, from strafing units to destruction physics, while developers working on the game itself boast of being able to conquer sky-scraping hive cities and customize Space Marines' fingers.

Still, few are as animated as Simon Mann (product owner – campaign design) and Andy Hall (principal narrative designer). Sitting down to discuss all things Total War: Warhammer 40,000, the pair's enthusiasm is immediate – and as they unveil the true scope of their game's ambition, their excitement proves infectious.

"Like you'd expect in the tabletop game, a unit of your warriors isn't just made up of one unit type. It's not the same person: they've got different specialists, different weapon styles," Mann explains, pointing to Space Marines as an example. "If you play the tabletop, a sergeant with an intercessor squad is armed with a chainsword and bolt pistol. They're good in both melee and ranged."

These loadouts can be changed by players, from picking their weapon loadouts to even more in-depth customization via a fully-fledged unit painter. Neither Mann or Hall seem phased by the balance of power between ranged and melee combat. The confidence brings to mind Total War: Warhammer, which prompted fears – since proven unfounded – over how flying units, godlike beings, and spellcasting would gel with the once exclusively historical series.

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Also here is the info of a german article about how campaigns will work in total war 40k

Gamestar Article: How campaigns will work in Total War 40k

Galaxy Map

• The galaxy map functions as a hybrid between a campaign selection menu and meta-progression. You don't actually move armies or end turns here, instead you're given an overview of the galaxy at large and offered several campaigns to take part in.
• Those campaigns are split into three types: Full campaigns, short campaigns, and singular decisive battles. Full campaigns will be closest to traditional Total War, set in a full star system meant to be longer and finished over multiple sessions. Short campaigns will feature only a few planets and be intended to be completed in a single evening. Singular battles are self explanatory. So it's a "choose your commitment" type system
• Campaigns can either be generated, or narrative. So there will be campaigns set in handcrafted systems/locations from the lore, with narrative objectives and factions, and also campaigns that are more randomized
• Completing campaigns carries over effects and changes to the galaxy layer and potentially future campaigns. The example they gave was helping the Imperial Guard in one campaign leads to allied Imperial Guard forces showing up to support you throughout battles in your next campaign
• It's unclear how much management will be done at this layer, but the article does seem to hint that you'll manage the systems you've taken in campaigns

Campaign Layer

• The campaign layer sounds like it will function like a traditional total war campaign. You have armies, fleets, resources, infrastructure to manage, and you move them around the map
• Campaigns will feature multiple planets in single systems/sectors. Planets will be different biomes and states of war (some may have ongoing battles, be hive planets, etc)
• Planets will be separated by space (seemingly connected by lanes, if the gameplay preview is anything to go by), which will be traversed by your fleets. Similar to the role the sea played in previous total war's
• Upgrading fleets and fighting space battles was mentioned, but those details aren't being revealed yet

Planets

• Each planet will function like a little mini total war campaign map.
• Continents are stated to be about the size of provinces in current Total War. Armies move around here like a normal Total War map, where you move them around on a board essentially.
• Instead of building cities you are mostly relegated to building outposts and bases. Cities will still play a part however, they will be more like independent entities that you occupy and then manage from there instead of building and upgrading yourself. Constructing buildings and recruiting units in them was mentioned, so it seems like it'll be a similar to current city management just more horizontal rather than vertical.
• Your fleets can interact with planets by doing orbital bombardment, exterminatus, etc.