Developer Q&A: What to expect from Shadow of the Warmaster?


“This is but a glimpse of the times to come.”

Warmaster Horus

Last week we opened special channels of communication for the community to send us questions for a new Q&A. We are incredibly grateful for the interest and love for the game, and since, as expected there were many questions regarding the new expansion, we thought it would be better to write a web post answering the most common doubts and concerns.

A new cycle begins

After 9 major content expansions released in the four and a half years since the game launched, the card pool has grown massively, and all the Astartes Legions and other major factions of the Horus Heresy have made it into the game. Moreover, the Horus Heresy setting has also evolved massively in this time, with the latest tabletop version significantly increasing its scope and reach. It is now time to begin a new cycle!

The upcoming Shadow of the Warmaster expansion will bring a brand new set of cards for the first four Legions in the game: Sons of Horus, Emperor’s Children, Death Guard and World Eaters, as well as a large new set of neutral cards. At the same time, the cards from the base Isstvan III set will become ‘legacy’ cards, and will only be playable in a new ‘Legacy’ game mode and in direct duels. The normal Ranked, Practice and Event modes will no longer feature legacy cards.

Moreover, the expansion will bring a complete rebranding of the game, with a brand new logo and cover art, as well as numerous graphical improvements and other unannounced surprises!

Why create a Legacy mode, instead of simply adding more cards?

The most important reason is that as the card pool grows, it becomes increasingly difficult for new players to start playing competitively. To keep new players from having to learn and collect an ever increasing pool of cards, we believe the time is right to cap the number of cards usable in ‘normal’ game modes.

On top of that, we want to bring a fresh new take to these Legions, both in aesthetics and game mechanics. You will find a few familiar faces in the new collections, as you can’t really do the Sons of Horus without Horus, but all of the new armies have been built from scratch. The card lists, artwork, voice lines and mechanics have been created as if it were a whole new faction joining the game. They are also based later in the Heresy timeline than the original Isstvan III set, the four traitor Legions having openly pledged their allegiance to the Warmaster. Altogether, we are aiming to turn them into the most polished, up-to-date and fun armies in the game!

We understand that removing cards from the normal game modes can be frustrating for players who are fond of those particular cards, and who may have spent time and money to collect them. But there comes a point in the life of every collectible card game in which it becomes a necessity to do so, whether explicitly (through set rotation) or indirectly (eg. through gradual power creep).

We have decided to use an explicit but gradual approach, starting with the cards that have been in the game the longest. We will also make sure that there’s always room to keep playing with legacy cards, whether that’s in the new legacy mode, in direct challenges with other players, or in community-led tournaments which decide to allow legacy cards.

To build a new Imperium, the old one must burn.

Abaddon, First Captain of the Sons of Horus

How will the Legacy mode work?

Once the new expansion begins, constructed play will be divided into two different categories: Standard and Legacy. The Standard mode will be similar to the current system, with Ranked and Practice options, with the only difference that decks won’t be able to include legacy cards.

The Legacy mode, on the other hand, will allow players to include legacy cards in their decks, as well as non-legacy ones. Legacy mode is not meant to be a competitive game mode, so it won’t have season prizes or separate Ranked and Practice options. It will nevertheless have its own ranking system and leaderboard, separate from that of Standard mode, to facilitate a matchmaking system that tries to pair players of similar strength, and to provide some bragging rights to those who perform best each season.

Will other cards also become legacy? If so, when?

Expansions will not rotate out of Standard mode all at once. The first Shadow of the Warmaster faction that will join the game will be the Sons of Horus on the 26th of January. When the day comes, the original Sons of Horus faction will become unavailable for play in Standard mode, and only playable in Legacy Mode. The rest of the factions will follow the same procedure, whenever a new faction from the Shadow of the Warmaster expansion is released, its original counterpart will become only available for play in Legacy Mode.

At the end of the Shadow of the Warmaster expansion release season, all Isstvan III cards will have rotated out of Standard. Future expansions will gradually release new cards for the other armies and rotate their initial sets to Legacy mode. This will follow the same order in which armies joined the game, ensuring all cards can be played in Standard mode for several years after their release. 

The next expansion after Shadow of the Warmaster, planned for the second half of 2023, will focus on the Isstvan V loyalist Legions: Iron Hands, Salamanders and Raven Guard.

No turning back. I will conquer the future, or erase it.

Warmaster Horus

Will it be possible to collect legacy cards?

For the most part, no. The Isstvan III crates will no longer be available in the shop, and legacy cards will no longer appear in reward or faction crates. They may occasionally appear for sale again on a temporary basis, but there are no specific plans for that at the moment.

Will there be changes to the other single-player campaigns?

The existing single-player campaigns for Sons of Horus, Emperor’s Children, Death Guard and World Eaters all feature many cards that are becoming legacy, so we don’t consider them adequate for new players. They will remain accessible in the Campaigns menu, but will be taken out of the rotation system which opens up a different Campaign for free every few weeks. Therefore, they will only be playable by those who buy (or have already bought) access to them.

We are also considering creating new single-player campaigns are/or updating the current system somewhat. We can’t share any concrete plans about it at this point.

Will there be new mechanics for the legions in the expansion?

Yes! In many cases, the new card sets will bring new unique mechanics, while also staying true to their lore and core gameplay style. For example the Sons of Horus will boast a new ‘Speartip’ trait, while the Death Guard will get a complete rework of the Poison mechanic, to make it more dynamic and fast-paced.

Will alternate art versions of warlords still be usable in standard game modes?

Yes! Although with some changes. Many warlords, such as Horus and the other Primarchs, will get a new version in the upcoming expansions, boasting new abilities, artwork and voiceovers. Once players collect these, if they owned an earlier alternate art version of the warlord, they will be able to use it as a cosmetic variant. Eg. Players who own Horus’ alternate art will be able to use its artwork and voiceover in Standard mode, but only once they’ve collected the new Horus card, and it will use its new card abilities instead of those of the legacy version of Horus.

This new approach will only affect the new warlords released in the game. In Legacy mode, things will continue to work as before: alternate art warlords will appear as separate cards in the deck editor, with their earlier abilities, and players will be able to use them even if they don’t own the base version of the warlord.

What delights do you have for me, I wonder?

Fulgrim, Primarch of the Emperor’s Children

What are the design aims for the new card sets?

In general, the aim has been to make each army fun to play, dynamic, with a range of viable strategies and deck archetypes, true to their lore, and also up to date with their latest developments in the Horus Heresy novels and tabletop game. For example, the four Legions in the Shadow of the Warmaster expansion will no longer be set at the start of the Heresy, but rather later on when they had fully given themselves to the cause of the Warmaster.

Beyond that, each Legion has its own unique circumstances. In some cases, such as the Sons of Horus, their signature fast and direct style will remain the same, even as they get a new trait to bolster it. In other cases, as with the Death Guard, the new set will aim to change their playstyle to a more dynamic one, to make them more fun to play with and against.

Sota-Nul - Horus Heresy Legions

What will happen with neutral cards?

All neutral cards in the Isstvan III base set will become legacy cards once the Shadow of the Warmaster starts, together with the Sons of Horus base set. To make up for it, a new set of neutral cards is on the way, much larger than in earlier content expansions!

Part of the new neutral cards will be released right from the beginning, to replace some core cards that are often created or used by other cards, such as lesser and greater daemons. The remaining neutral cards will be released as a separate content drop, after the card sets for all 4 Astartes Legions are live, just as in previous expansions.

Will Mechanicum get its own sub-faction, similar to Solar Auxilia or Cultists?

We have considered creating a Dark Mechanicum keyword more than once, so it may well happen at some point!

You have no idea what I’m capable of.

Calas Typhon, First Captain of the Death Guard

What about the current tutorial and the initial Isstvan III campaign?

The current onboarding, including the tutorial and the Isstvan III single-player campaign, will no longer be playable once the expansion begins, since all the cards that appear in it are becoming legacy cards. Players will also stop receiving the current starter deck, with Loken as warlord.

In its place, a brand new tutorial will be introduced, relying primarily on all the new cards in the Shadow of the Warmaster expansion. Existing players will be able to play it if they want.

A new starter deck will also be handed out, both to new and existing players, regardless of how far they had progressed into the game!

Lord of the Flies - Horus Heresy Legions

What else is planned ahead of the expansion release?

Even though the Shadow of the Warmaster expansion is just around the corner, there is plenty happening in the game between now and then! A new Raid event has just started, with Horus boasting his amazing new artwork as a memorable Epic Boss, and the renowned Lord of the Flies on the line, in what may well be its final chance to become a collectable warlord.

On top of that, another special event in January will serve to bid farewell to the cards moving into Legacy mode, and an unexpected character may be getting a fantastic new alternate artwork!

This is all for this developer Q&A. We hope it brings answers to your most burning questions, and you are excited about the upcoming Shadow of the Warmaster expansion. It will bring the biggest set of new cards yet, with interesting mechanics and great artwork, as well as many other improvements.

A new cycle is about to begin. Are you ready?

We built this Imperium, it’s time to take what is ours.


The Horus Heresy: Legions is available on Steam, iOS and Android.

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