All Warhammer 40k Codex release dates from 10th Edition

As 10th edition draws to a close after three years, Games Workshop has now published a new Warhammer 40k codex (or at least an index update) for a full 30 playable armies - and it's hinted at one more mysterious book before the edition ends. Read on for a full breakdown of all the 10th edition codex release dates, the latest news on upcoming codexes, and key info on how to use these crucial rulebooks in your games.

If you're new to Games Workshop's premier sci-fi miniature wargame, our expert guide to the Warhammer 40k factions will help you get oriented in this huge sci-fi world. And for all the info on the upcoming new version of the game, read our complete rundown on Warhammer 40k 11th Edition.

For now, though, let's run through the latest official codex rulebooks - some already released, some scheduled, and others as yet mired in mystery. You can click the links below to find the info you need:

Confirmed 10th Edition codex release dates

The latest Warhammer 40k Codex is Codex: Drukhari, which went up for pre-order on September 27, 2025, and released on October 11.

Of the at least 27 10th edition codexes we expected to arrive over the (roughly) three years of the edition, a whopping 30 factions now have either a codex or an updated index. This includes a re-release of Index Deathwatch - which was briefly deprecated by Codex Imperial Agents - and mid-edition refreshes of both Index Chaos Daemons and Index Imperial Knights.

Here's a table showing all the codexes (and updates) released so far:

If you're wondering when a particular codex released during 9th edition 40k, check out our guide to 9th edition codexes.

Upcoming Warhammer 40k codex news

Does Games Workshop have one last upcoming 10th Edition codex still waiting in the wings? Well, maybe. But if it does, it'll only be Space Marines - and time is running out for this mystery book to finally emerge.

The Drukhari marks the last codex confirmed for 10th edition, but we're still expecting one more thing: it's just a mystery what it is. That's because one of GW's 2024 release 'roadmaps' included the above silhouette of a Primaris Space Marine Reiver, marked as coming in "the future".

Our early impression was that, as in 8th Edition (2017-2020) GW had a second 10th Edition 'dex in store for the Adeptus Astartes before the edition draws to a close in Summer 2026. That was, until GW went on a bit of a spree with new Ultramarines models and reveals in October and November, and dropped a comedy trailer suggesting something more substantial was coming. Suddenly we're wondering if an Ultramarines Codex supplement is on its way.

The surprise release of Codex Imperial Agents in 2024, which collected the rules for Inquisitors, Rogue Traders, Imperial Assassins, and the Deathwatch, seems to bode well for further new (or resurrected) factions to get standalone armies.

But with mere months left until the expected release of Warhammer 40k 11th edition, it seems unlikely GW will give us such a large surprise gift before the sun sets on tenth edition.

All free Grotmas detachment PDFs

In December 2024, Games Workshop released one new, free, one-off expansion PDF for each army as part of its 'Grotmas Calendar' promotion. The 2025 Grotmas Calendar wasn't quite so heavy on new rules, but we did get another six shiny new detachments to play with. You can find all linked below.

Each PDF adds a full detachment to the game, complete with detachment rule, four Enhancements, and six Stratagems, to offer a new way to play each faction. These detachments are available to use in games alongside the ones provided in your faction's codex.

Download the 2025 Grotmas detachment PDFs:

• Astra Militarum - Grizzled Company
• Chaos Space Marines - Nightmare Hunt
• Blood Angels - Rage-cursed Onslaught
• Aeldari - The Serpent's Brood
• Emperor's Children - Court of the Phoenician
• Space Wolves - Saga of the Great Wolf

Download the 2024 Grotmas detachment PDFs:

• Death Guard - Flyblown Host
• Dark Angels - Lion's Blade Task Force
• Tyranids - Warrior Bioform Onslaught
• Thousand Sons - Hexwarp Thrallband
• Adeptus Mechanicus - Haloscreed Battle Clade
• Necrons - Starshatter Arsenal
• Adeptus Custodes - Solar Spearhead
• Chaos Knights - Iconoclast Fiefdom
• Imperial Knights - Questor Forgepact
• Grey Knights - Warpbane Task Force
• World Eaters - Vessels of Wrath
• Black Templars - Wrathful Procession
• T'au Empire - Auxiliary Cadre
• Blood Angels - Angelic Inheritors
• Adepta Sororitas - Champions of Faith
• Space Wolves - Champions of Fenris
• Genestealer Cults - Final Day
• Leagues of Votann - Hearthband
• Chaos Daemons - Plague Legion
• Chaos Daemons - Scintillating Legion
• Chaos Daemons - Blood Legion
• Chaos Daemons - Legion of Excess
• Astra Militarum - Bridgehead Strike
• Orks - Taktikal Brigade
• Drukhari - Reaper's Wager
• Aeldari - Armored Warhost
• Chaos Space Marines - Creations of Bile
• Space Marines - Librarius Conclave
• Imperial Agents - Veiled Blade Elimination Force
• Deathwatch - updated Index

How do I redeem Warhammer 40k codex codes?

You'll find a unique Warhammer 40k codex code in the back of each printed Codex. You can register this code on your MyWarhammer account, which will in turn unlock all the datasheets and Detachments from the Codex in the Warhammer 40k app.

You can then use that data in the Battle Forge army builder. You will be limited to just one army list at a time in the app, unless you also have a Warhammer+ subscription.

Warhammer 40k codexes FAQ

Codexes are bread and butter to long time Warhammer 40,000 fans; we know what they're for, we know how they change the game, and boy oh boy do we know how much they cost.

But if you're new to the hobby, the whole concept of them can be a bit bewildering. The idea of needing another rulebook, on top of the actual rulebook, is tough enough - but buying a new one every three years? It's one of the rougher parts of the 40k hobby, and it bears a bit of explanation. Read on for a breakdown of the nuts and bolts of what codexes are, how they work, how to use them, and how they may change in the future.

What is a Warhammer 40k codex?

Codexes are Games Workshop's supplementary rulebooks for each playable faction. Alongside the core rules, each individual Warhammer 40k army has its own codex where you'll find rules for all its units, as well as any army-wide rules or other choices you'll make when you construct a list.

What do you use the codex for in games?

During a game of Warhammer 40k - especially when you're new to the game or learning a new faction - you'll need to refer to your army's codex frequently to check key rules and statistics about how your army functions.

Most importantly, you need to know the stats for each unit, its weapons, and abilities. For example, you'll find yourself double checking know how many inches it can move each turn, the range and power of its shooting attacks, or how effective its armor is at preventing damage. Over time, you'll know more and more of those key numbers from memory - but it's important to have the codex on hand to double check, so you don't accidentally cheat!

Codexes are also super important before the game, as they include the rules for your army's possible Detachments and the Stratagems each one offers. These are army building choices which shape your game plan by applying different army wide buffs, as well as specialized abilities to trigger at crucial moments during the game.

Can I buy a digital or PDF version of my codex?

No, Games Workshop doesn't sell PDF versions of codexes. Since the launch of the official Warhammer 40k app in July 2020, the only official, GW supported way to view a codex's rules in digital form is to buy a copy of the physical book, then redeem its unique code to unlock it inside the app. We've written instructions on doing that - see above.

Prior to 2020, new 40k codex books were available in both printed physical and ebook formats. They were never sold as PDFs, so any codex PDF you encounter online is likely to be an unauthorized pirate copy.

How do Games Workshop's codex release dates work?

During each three year long 'edition' of Warhammer 40k, GW normally releases one new codex for each playable army in the game. Typically, they're released in groups of one or two, once every two months or so.

How and when these codexes are released can vary, depending on how fundamentally the current 'edition' has adapted the game's core rules. Because 10th Edition changed the core rules significantly in 2023, GW completely retired all 9th Edition codexes from the game, and provided a full set of free 'index' rules for each army, for fans to play with until their army's new full codex arrived.

As codexes were released, they superceded the Indexes, updating rules and points, and adding new detachments that provided different ways to build an army that complete with with new abilities, enhancements, stratagems.

What about old codexes - can I use those?

As soon as an army's latest Warhammer 40k codex is released, the previous edition's rules are no longer valid in 'Matched Play' games. That means tournaments and organized play in general will always use only the most up to date codex rules, and all earlier books are no longer usable.

However, many players enjoy running games of older editions, deliberately using the rules from previous editions' core rules and codexes, to play the game 'as it was then'. Your old codexes might not be tournament legal, but they don't simply disappear!

Got a burning question about your codex? You'll find a friendly and helpful community in the Wargamer Discord. To keep up with the latest news about upcoming codex releases, subscribe to the Wargamer newsletter.