The Horus Heresy has always been a setting of shattered alliances, broken brotherhoods, and massive, apocalyptic wars—but one thing’s never changed: no Legion fights alone forever.
From the grim unity of the Dropsite Massacre to the brutal siege of Prospero, the stories of the Age of Darkness are filled with moments where multiple forces fought side by side. Now, the new edition of Horus Heresy is making it easier than ever to bring that same kind of tactical (and narrative) synergy to your tabletop games.
The Basics: How Allied Detachments Work
In the new ruleset, adding allies to your force is refreshingly simple. All you need to know is that an Allied Detachment must come from a different faction than your primary army, and that you can’t spend more than 50% of your total points on allied units overall. That’s it for restrictions. You can include multiple allied detachments, so long as you stay within that 50% limit.
Each Command slot you fill in your main force opens up the ability to add an auxiliary detachment. This system isn’t just flexible—it’s smart. You’ll need at least one commander in the allied detachment to start unlocking more specialized units like Retinues or faction-specific elites, but you don’t need to mess with Apex detachments or complicated exceptions. What you can’t include are High Command officers, Primarchs, or other major warlords from the allied side—which feels narratively appropriate. After all, Horus isn’t likely to play second fiddle in your army.
Narrative Power: Why This System Feels Right
What makes this such a win for both casual and narrative players is how true it feels to the setting. Picture Iron Warriors supported by corrupted Mechanicum automata. Or a shattered Raven Guard remnant getting backup from a Solar Auxilia cohort trying to hold the line. Want to build a force of Shattered Legions survivors? This new system supports that without needing convoluted house rules.
Even better, the ally rules don’t feel like an afterthought. You’re encouraged to use them creatively, whether to represent narrative ideas or to simply field that one model you love painting but can’t justify building a whole army around.
Lords of War Detachments: Big Guns, Big Drama
Now, the Lords of War Detachment is a bit different. This lets you spend up to 25% of your total points on big-ticket items, and these can be from your main faction or from any other faction. That means yes, your Ultramarines can roll into battle with a Knight banner from House Cadmus, or your Sons of Horus could bring a Warlord Titan for maximum heretical overkill.
This detachment is perfect for showcasing centerpiece models. It’s also a huge win for those who’ve been sitting on a Titan kit, waiting for a chance to justify building and fielding it.
Hobby Wins: Try Before You Buy
There’s a hobby bonus to all this too. Allied detachments are a fantastic way to dip your toes into a new faction. If you’re Heresy-curious about Solar Auxilia or Mechanicum, but not ready to commit to a 3,000-point painting project, this system is your golden ticket.
For example, a Centurion, six Saturnine Terminators, and a Saturnine Dreadnought clocks in at under 1,000 points. That’s enough to support your army on the field and give you a taste of a whole new painting and playstyle vibe. It’s bite-sized but effective—and it might even be your next full army someday.
The Age of Darkness Just Got Way More Collaborative
Whether you’re here for the lore or the list-building, this new allied system makes the Horus Heresy feel bigger—and truer to the epic scale of its universe. It empowers narrative players to tell better stories and gives competitive players flexible tools to build well-rounded, synergistic lists. Even better, it helps collectors and painters get more mileage out of that one beautiful unit they’ve had their eye on.
Tomorrow brings lore drops on the Loyalist Legions, so stay locked in. And hey—if you sign up for the Warhammer newsletter before June 29th, you could win a Heresy prize bundle. Primarch included. Just saying.
And remember, Frontline Gaming sells gaming products at a discount, every day in their webcart!
