Secret Sanguinala 2025 Schedule (all times are 9pm/2100 US Pacific time):
October 5 - 15, Nominations
October 16 - 30, Signups
October 31, Assignments sent out
December 17, Assignments due
[Pinch Hitting occurs]
December 24, Gifts revealed
December 31, Creators revealed
Minimum requirements:
One fic of 500+ words or one piece of clean lineart meeting these requirements:
- Complete as posted
- Does not contain any of the recipient's stated Do Not Wants
- Focuses on a requested relationship or character
For more details, see the complete FAQ on the AO3 collection. Questions not covered in the FAQ? Ask!
The Warhammer 40,000 Summer Fest Exchange is back for 2026!
This fandom event is a Warhammer 40,000/Horus Heresy-focused gift exchange for fanart and fanfiction, hosted on AO3 – you can see previous years' gift collections here: 2022 | 2023 | 2024 | 2025.
Sign up to write a fanfic or create a piece of fanart, and receive a story or artwork in return!
Schedule:
May 15–May 31: Nominate your favourite characters and pairings
June 1–June 14: Sign up for the exchange
June 14–June 15: Matching and assignments go out
August 2: Assignments due – deadline countdown
August 15: Works go live (unless delayed for pinch hits)
August 22: Creators are revealed; the collection will remain open for treats
All deadlines are 3:59pm GMT | 5:59pm CEST | 11:59am EDT | 8:59am PDT.
👉 You must be 18+ and have an AO3 account to participate.
For information on how to sign up and participate, see the AO3 exchange profile.
Happy Sanguinala - we've made almost 80 new works of Warhammer 40k/Horus Heresy fanfic and art! Please remember to thank your gifter(s) for the hand-crafted presents.
If you wanted to make more treats and ran out of time, never fear - the collection will remain open for any additions you'd like to sneak in there. Late presents just make Sanguinala last longer!
Thank you to everyone who has participated! Go forth and enjoy the collection <3
merry FUCKING sanguinala, i havent seen this one reposted here (or maybe im blind) so you all now get to see this thing and also have your very own cutout sanguinius
The deadline has passed! What a handsome haul we got here.
If you don't see a Sanguinala gift on your gift page, don't panic! We have a few people who've been in contact and are still working, and a few gifts in progress to cover defaults.
If you find yourself impatient and need a distraction, consider making treats! Pick a request that sounds like fun, make something for it, then come back to the profile and hit "Post to Collection" to add it! Make sure you get the treat recipient's AO3 account filled in on the posting form so they get notified when everything goes live.
Just under a week to deadline! Hope those presents are coming along well.
We currently have one assignment in need of a new home! If you could take the following assignment, please DM or send an email to [email protected] with your AO3 username. Minimum requirements: a complete fic of 500+ words or a piece of clean lineart filling one of the requests, featuring a requested character/relationship, avoiding stated Do Not Wants.
Solo: Belisarius Cawl
Belisarius Cawl & Any Adeptus Mechanicus character
Solo: Alpha Primus
Belisarius Cawl & Alpha Primus
Do want
• Cawl being up to some good old-fashioned back-stabbity Adeptus Mechanicus politicking/techno-theological quarrelling. You're welcome to bring in any tech-priest original or canonical character (anyone from the cast of Forges of Mars or Dominion Genesis would be a plus, but by no means mandatory) for flavour.
• Any Primus-centric story, a character study or a wild adventure; Cawl, Qvo and the crew of the Zar Quaesitor may show up and be a significant part of the story, but I'd like to see our surly freak of science witch Astartes take the spotlight.
Do not want
Out-of-universe AUs (eg. modern world, coffee shop, historical), popular memes and fanon theories with no source in current lore being taken for granted as canon (eg. Krieg shovels, "Leandros broke the Codex Astartes by reporting Titus to the Inquisition instead of the UM chaplains"), trans headcanons, omegaverse, scat, pregnancy, underage, feederism, tooth-rotting fluff, x reader, kidfic.
General likes
Canon-typical grimdark and absurdism, military sci-fi, canon-typical religiosity/heresy, emotional gut-punches, dark humour, mature to explicit sexual content (the whole spectrum from consensual to dubious to noncon is fine), exploration of power dynamics, body horror, cyborg fuckery, character death and coping with grief.
Request 2
Commissar Maugh/Colonel Thyran
Commissar Maugh & Colonel Thyran
Fanart
Fanfiction
Do want
I really liked the friendly, trusting relation the Krieg colonel and the commissar-general had in the siege of Vraks novel, slowly getting older together in a military culture that frowns upon surviving and aging rather than dying in the Emperor's service, and that moment when Thyran sees Maugh's corpse displayed as a trophy by Zhufor the Impaler and is instantly ready to sword-fight the bastard and keep him pinned into place while the Krieg troopers blast them both to bits? You get my point. I'd love to read more of these two together. Friendship or ship, either is fine.
Do not want
Out-of-universe AUs (eg. modern world, coffee shop, historical), popular memes and fanon theories with no source in current lore being taken for granted as canon (eg. Krieg shovels, "Leandros broke the Codex Astartes by reporting Titus to the Inquisition instead of the UM chaplains"), trans headcanons, omegaverse, scat, pregnancy, underage, feederism, tooth-rotting fluff, x reader, kidfic.
General likes
Canon-typical grimdark and absurdism, military sci-fi, canon-typical religiosity/heresy, emotional gut-punches, dark humour, mature to explicit sexual content (the whole spectrum from consensual to dubious to noncon is fine), exploration of power dynamics, body horror, cyborg fuckery, character death and coping with grief.
Request 3
Merek Grimaldus/Zarha Mancion
Merek Grimaldus & Zarha Mancion
Do want
Helsreach left me with a mighty need for more Grimaldus and Crone of Invigilata interactions. Kind-eyed hard-ass Reclusiarch out to prove himself in a battle he did not want to be stuck into and ageing Princeps closer and closer to slipping out into her Titan's machine-spirit, barbed mutual respect through fundamentally irreconcilable lives and faiths. If you can make it work in a shippy way (strictly platonic or freaky with a ton of Collegia Titanica mecha mindfuck), go for it.
Do not want
Out-of-universe AUs (eg. modern world, coffee shop, historical), popular memes and fanon theories with no source in current lore being taken for granted as canon (eg. Krieg shovels, "Leandros broke the Codex Astartes by reporting Titus to the Inquisition instead of the UM chaplains"), trans headcanons, omegaverse, scat, pregnancy, underage, feederism, tooth-rotting fluff, x reader, kidfic.
General likes
Canon-typical grimdark and absurdism, military sci-fi, canon-typical religiosity/heresy, emotional gut-punches, dark humour, mature to explicit sexual content (the whole spectrum from consensual to dubious to noncon is fine), exploration of power dynamics, body horror, cyborg fuckery, character death and coping with grief.
Request 4
Leandros/Demetrian Titus
Thrax/Demetrian Titus
Any Adeptus Astartes character/Tyranids
Original Adeptus Astartes character/Tyranids
Do want
• Leandros/Titus: Post SM2, strong and complex feelings, pining, guilt, catching up with how both men have changed since the events of Graia, the slow and bumpy road to reconciliation... or a Chaos Marines AU, or a bad ending to SM1 AU where the Inquisition detains Leandros along with Titus for suspected corruption, and they endure captivity and its aftermath together. In any case, where viable plot-wise, porn with intense feelings is welcome and encouraged.
• Thrax/Titus: The Inquisitor's interest in cracking the enigma of Titus' unexplainably Chaos-proof mind gets more up close and personal, with a little help from whatever daemon shit is slowly infiltrating Thrax's own mind. I won't say no to explicit Inquisitor-on-captive-Astartes dubcon/noncon, but would rather prefer it to be more geared toward psychological horror darkfic, with Inquisitorial (and daemonic) fuckery in copious amounts.
• Any Space Marine or original Space Marine/Tyranids: Your free-space centre square on the monsterfucking bingo card. Make the big lads suffer, and the hive mind feast.
Do not want
Out-of-universe AUs (eg. modern world, coffee shop, historical), popular memes and fanon theories with no source in current lore being taken for granted as canon (eg. Krieg shovels, "Leandros broke the Codex Astartes by reporting Titus to the Inquisition instead of the UM chaplains"), trans headcanons, omegaverse, scat, pregnancy, underage, feederism, tooth-rotting fluff, x reader, kidfic.
General likes
Canon-typical grimdark and absurdism, military sci-fi, canon-typical religiosity/heresy, emotional gut-punches, dark humour, mature to explicit sexual content (the whole spectrum from consensual to dubious to noncon is fine), exploration of power dynamics, body horror, cyborg fuckery, character death and coping with grief.
December 3 already what the heck!!! That means we are two weeks from deadline. Good luck to everyone still working! (Most of us) Heckin congratulations to everyone who's already posted! (A valiant few)
If you know you won't be able to complete your assignment, please default by going to the collection profile, clicking on "My Assignment", and then hitting the "Default" button. There's no penalty for doing this, and it lets the grots know to start hunting down someone else to fill the assignment, so everyone still gets a gift.
If you're interested in being able to receive treats, you may want to go to your Preferences page on AO3, scroll down to the Collections, Challenges and Gifts section, and make sure you have non-assignment gifts enabled:
Older AO3 accounts have this setting turned on by default, but ones from the last couple of years default to having it off. You'll be able to receive your assigned gift either way, but for the possibility of extras you need to have it checked.
That's all the news for now! Good luck out there in the gift-making trenches.
Assignments are out! You'll find them in the email associated with your AO3 account or, if that's slow to show up, by going to the exchange profile page and clicking the "My Assignment" link that now appears on the left. Things to remember:
You only need to create one work for one tag! If you get inspired for more that's great but you don't need to.
The tag you create for can be one you didn't originally offer! If something else in your recipient's requests sparks your imagination, go for it.
A few participants signed up with blank optional details. If your assignment looks like that, it's a license to make whatever you'd like with your chosen tag.
If that's too much freedom and you want more info (or you have questions about details you did get), please contact the mod at this tumblr account or at [email protected] to send an anonymous query to your recipient.
Remember, the gift you're making is a SECRET: don't share any identifying information about what you're making for the exchange on your tumblr, other social media, public discords, etc. You can talk to a friend, spouse, or particularly trustworthy grot in private! Just make sure it's no place the recipient might stumble across it.
Assignments will go out within 24 hours, after the grot matching team has had a chance to bash the automated matches around a bit. Lots o' good requests to hand out here!
Signups are open! You will need to request and offer at least 3* characters or relationships from the extensive list of nominated tags. In your requests you can suggest prompts for things you'd enjoy, and list DNWs (things you Do Not Want) that should not be included in gifts for you.
The signup form has more detailed instructions and the full exchange rules are on the profile -- please make sure you're comfortable with the rules before you sign up.
If you're unsure what to offer or want to see other people's ideas for inspiration, you can browse the request summary to see other people's prompts.
Get out there and get requesting!
*and at most 200, due to the limitations of the signup form.
Signups are open! You will need to request and offer at least 3* characters or relationships from the extensive list of nominated tags. In your requests you can suggest prompts for things you'd enjoy, and list DNWs (things you Do Not Want) that should not be included in gifts for you.
The signup form has more detailed instructions and the full exchange rules are on the profile -- please make sure you're comfortable with the rules before you sign up.
If you're unsure what to offer or want to see other people's ideas for inspiration, you can browse the request summary to see other people's prompts.
Get out there and get requesting!
*and at most 200, due to the limitations of the signup form.
Out of 583 nominated tags, 326 have been requested at least once.
The most-requested tags right now: Roboute Guilliman/Aeonid Thiel, Ezekyle Abaddon/Iskandar Khayon, Raum/Argel Tal, and Orikan/Trazyn.
The most-offered tags right now: Orikan/Trazyn, Original Chaos Space Marine/Original Astra Militarum Character, Original Chaos Cultist/Original Traitor Guard, Alastor Rushal/Jago Sevatarion
You can find the stats for your favorite ships in the signup summary!
Signups are open! You will need to request and offer at least 3* characters or relationships from the extensive list of nominated tags. In your requests you can suggest prompts for things you'd enjoy, and list DNWs (things you Do Not Want) that should not be included in gifts for you.
The signup form has more detailed instructions and the full exchange rules are on the profile -- please make sure you're comfortable with the rules before you sign up.
If you're unsure what to offer or want to see other people's ideas for inspiration, you can browse the request summary to see other people's prompts.
Get out there and get requesting!
*and at most 200, due to the limitations of the signup form.
