This is a Warhammer 40k total conversion for OpenXcom, based on an earlier space marine mod by Ryskeliini. As Force Commander for the Imperium of Man on a planet beseiged by Chaos, you must find a way to end the Warp Storm and purge your world!

By Ryskeliini, bulletdesigner, ohartenstein23, and many contributors from the OXC forums

Installation and Update Instructions Video:


  • Download and install OpenXcom Extended (OXCE), version 5.5 or later, by Meridian and Yankes
  • Run OXCE after copying the UFO files to generate the user/mods folder
  • Download the 40k files, and unzip into the mods folder
  • Run OXCE, go to Options > Mods and select "40k" from the drop-down menu at the top
  • (Optional) If the Music is playing the UFO soundtrack, check Options > Audio > Music Format, and set it to "Auto" or "OGG" if it isn't one of those.
  • (Optional) Turn on the Stat Strings mod under Options > Mods
  • (Optional) Turn on the Chapter Change mod under Options > Mods to change the look of your Space Marines to the Imperial Fists or the Blood Angels Chapters

Reduced Download Install:

  • If you already have the mod Version 020, want a smaller download, and are comfortable manually moving some files within the mod folder, pick the download.
  • Follow the instructions for Updating below, but when you remove the previous version, keep the folders 40k/Resources/ANIMS and 40k/SOUND.
  • After putting the updated 40k folder into user/mods, put the folders you kept from the previous version into the same places in the new version.
  • If the game doesn't work correctly after this, try the full download/update.


  • Save any current campaign in the Geoscape. Loading a Battlescape save from a previous version is more likely to cause bugs and crashes, and is not recommended.
  • Remove the previous version's 40k folders from your OXCE mods folder.
  • Download the new version's files and unzip into the mods folder. Your previous saves should be compatible if made during the Geoscape.


  • Big props to Ryskeliini for the space marine stuff and Dixone for the help
  • Used a lot of maps from Terrainpack so special thanks to Hobbes also so help on side


Sprites, sounds, maps, ruleset code etc:

  • All around thanks to everyone, I used lot of stuff from other mods for reference and change it to 40k universe
  • Background images from various internet sources


5 of 1044,790 (2 today)ohartenstein23


OpenXcom Extended (OXCE)
















Guest @guest

Amazing mod!

ohartenstein23 @ohartenstein23

Glad you're enjoying it!

TheDeparted @thedeparted

I would like to share a few thoughts with you after playing the mod for 4-5 hours. Please be advised that I'm a total noob at xcom:

1. It's one of the most polished mods I've ever played; the music is great, the sounds effects are on spot, and the gameplay is xcom;
2. The game crashes when trying to use the assault bike;
3. Isn't it a bit pointless to use Guardsmen once you've unlocked the Space Marine? (A suggestion if I may: the SM might use two spaces instead of one in the "Sky Ranger")

Thank you for a wonderful experience!

ohartenstein23 @ohartenstein23

Thanks for your feedback - I replied to your post on the forums about these points here:
The crash should be fixed in the next version (015).

TheDeparted @thedeparted

10x for your reply. much obliged. Is there any way to help the team? I suck at programming, but I'm fairly decent at editing text.

ohartenstein23 @ohartenstein23

If you'd like to do some proofreading of the in-game text, we'd appreciate it!

I've been working my way through the text in the file 40k/Ruleset/extraStrings_40k_us.rul, if you load it in a text editor, you can find the point up to where I've been proofreading. Send me any of the strings you've edited and we'll look at using that to update the in-game text.

TheDeparted @thedeparted

Cool. will do. Which text editor do you prefer/recommand?

ohartenstein23 @ohartenstein23

Notepad++ works pretty well for OXC rulesets, Visual Studio Code is free and there's an OXC ruleset validator for it:

Mostly anything that does plain text and doesn't have automatic formatting.

TheDeparted @thedeparted

K. I'm on it.

TheDeparted @thedeparted

The revised text is here.

prograde @prograde

Absolutely wonderful mod, even with the occasional quirks. I have a few concerns regarding the balance early on in the game (especially on lower difficulties when I always find myself getting swarmed by chaos raptors before having a chance to get to the mk7 tac armor).

I'd be very interested in enlisting my help in testing the game for bugs and balance!

ohartenstein23 @ohartenstein23

We've reworked the starting tech a bit so access to your first set of MK7 armor should be easier - when you research a marine "strategy," you unlock one of the variants. You can also always retreat from an enemy that's too tough, sometimes it's better to regroup and try again later.

We welcome more feedback, keep playing and letting us know what you think, either here or on the OXC forums:

Guest @guest

The names are wrong in the version i downloaded it (droppods=skyranger,stormtalon=interceptor)

ohartenstein23 @ohartenstein23

This issue is common when your operating system's default language is UK or GB English - the mod only supports US English right now. Go to the Options menu in the game and set the language to en-US.

Guest @guest

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ohartenstein23 @ohartenstein23

The original 016 release had a bug that had a chance of causing the wrong retaliation mission to occur - please either re-download or replace the alienRaces_40k.rul ruleset file with the one attached to this post:

doctor_medic @doctor-medic

Pretty good mod,it might not have the depth of content of mods like xpiratez or final mod pack but that allows it to focus more on specific aspects and refining them instead of quantity over quality.

ohartenstein23 @ohartenstein23

Glad you're enjoying the mod, doctor!

I wouldn't call Piratez or Final Mod Pack/X-Com Files unrefined or "quantity over quality," they're certainly well-refined and thought through. Most of the difference you're seeing is probably that the authors of Piratez and FMP/XCF take graphical resources from many disparate sources, while we end up having to make most of our own from scratch or from reference models in order to fit the lore and setting.

ohartenstein23 @ohartenstein23

To everybody using the Imperial Guard Operations path and Valkyrie Drop Transports - do not use the auto-equip function (default pressing the "z" key) in the pre-battle inventory screen! This will cause your first soldier to be stranded in the air. This will be fixed by the 018 release, but for now don't use auto-equip when deploying from the Valkyrie Drop Transport!

Edit: You can fix this by updating the rulesets contained in this forum post -

Guest @guest

I noticed that Krak grenades are not effective aganist chaos space marines, they can survive more than 4 grenades exploding in the same turn, cheeking the rulesets i noticed that the krak grenade launcher has a power of 80 and the hand krak grenade has only 100 of power, chaos tactical marine armour tends to have a 100 of armour points so the barely take any damage (even if they take, khorne tactical space marine have like 120 hitpoints, for reference), krak explosives might need to have an special damage type that has bonus aganist armour (i think it can be coded in the item ruleset and overrides the common damage types), this also goes for krak missiles that, if i remember well, have a power of only 150.

ohartenstein23 @ohartenstein23

On a direct hit explosives hit a unit's under armor, which is often weaker. The grenade launcher krak rounds will damage chaos marines ~50% of the time on a direct hit, and the hand grenades can even be one-hit lethal. The reason the launcher is weaker is that it can fire twice per turn and carries more rounds per unit weight than individual grenades. Since you can easily hit from out of line-of-sight with arcing weapons, I don't think buffs are necessary here.

Personally I find them to be right about where we want them - better than other equipment you get at the start for killing without first wearing down armor, but still leaving something to be desired. A well-placed krak grenade has a good chance of wounding a chaos marine and can often be tossed farther than the accurate range of most guns.

Also picking out Khorne Berserkers as an example was a poor choice, as they are particularly high HP.

Guest @guest

Yes, it's a bad example because this was from a playthorugh were chaos marines came early like in the third month (i still checked the latest version ruleset values to see if the stats were the same also khorne marines can still keep going even if mutilated, khorne blessings), but this also happens whit ork nobz, and, what about krak missiles?.
But overall for all armour piercing weapons for IG, i find the krak explosives to be unreliable and i tend to use lascannons and long las, and it's purely because of their stats that they have more potential on taking down armored units, but in tabletop, krak grenades can damage dreadnoughts, so i still think that krak weapons needs to have an anti-armour damage multiplier (munroe effect).
Also, armour gets damaged on this mod? because i havent seen that property in the wiki, neither in the ruleset code, can you explain?.

ohartenstein23 @ohartenstein23

Krak grenades were purposefully made not as powerful as in the tabletop, and that's important for the balance of the mod. Thrown weapons in general are strong tools in X-Com, as they tend to be accurate at longer ranges than firearms due to how arcing trajectories are calculated. They also hit the typically weaker under armor and can damage large units multiple times. Add on top of these factors the fact that you can bring a basically unlimited number of them to spam from out of the enemies' line of sight, and you can make the argument that you don't even need to bring firearms.

In the 40k mod, we wanted to limit the use of grenades to softening targets or cleaning up groups of weakened enemies, otherwise it would be the clearly less effective choice to use your lasgun or bolter instead of a belt full of krak grenades. The damage of the krak grenade is still much higher than many of your early weapons, making it a good choice when facing raptors or traitor marines, but not necessarily the best choice. Adding the ability to ignore or damage armor to a noticeable degree will put krak explosives a clear winner over any other tool you start the game with, and as such I'd rather they stay with their current stats.

By default, 10% of the damage a weapon does after piercing armor goes to reducing the armor value of the side it hit. In the ruleset, this functionality is determined by the ToArmor parameter. Many weapons in the mod have a ToArmorPre parameter as well, which means some armor damage is applied before piercing. Finally, there is also the ArmorEffectiveness parameter, which reduces the amount of armor a particular hit has to pierce though without changing the armor value itself.