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 5.3 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 Chapter

Reduced Download Install:

  • If you already have the mod Version 019, 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


3 of 953,427 (13 today)ohartenstein23


OpenXcom Extended (OXCE)














Guest @guest

I see the grey knights are new enemies. So I guess in the mods lore they invade the planet to purge all life by the order of the inquisition?

ohartenstein23 @ohartenstein23

The Grey Knights are in the mod to ensure the purity of the Chapter under your command.

ohartenstein23 @ohartenstein23

Continuing our streak of release-day bugs, here's a fix for sprites causing a crash when opening the bases screen, just replace the ruleset in 40k/Rulesets:

lasseronne @lasseronne

Do we have an ETA on the fix for the REGION_HULK_SITE bug? It is just because I get it in all my saves since 019.
Sorry if this sound in any way demanding, it is not meant to. I just really love this mod and want to play it :) and will just go back to 018 until then.

ohartenstein23 @ohartenstein23

I just pinned a fix for this in our discord server, check if you can download the ruleset from this link and put it in your 40k/Rulesets folder:

Version 020, which fixes a number of bugs, should come out within the next few days. It was delayed by the number of bugreports we received and some new features taking longer to implement than expected.

Guest @guest

Question: say I've lost 10 guardsman since day 1. It's feb 23.
In "montlhy costs" screen, under salaries, it tells me I still have them somehow. Could it be a bug? It was showing the right number (2) just before terror mission 2 I believe.

ohartenstein23 @ohartenstein23

Can you provide a save so we can look at it and see what's going on?

Guest @guest

I tried playing version 019 with a save from 018 (loaded from geoscape, not from battle), and got the following crash about a month in.

[18-04-2019_20-51-09] [FATAL] A fatal error has occurred: Region REGION_HULK_SITES not found
[18-04-2019_20-51-09] [FATAL] 0x7e0ad0 OpenXcom::CrossPlatform::stackTrace(void*)
[18-04-2019_20-51-09] [FATAL] 0x7e1f90 OpenXcom::CrossPlatform::crashDump(void*, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)
[18-04-2019_20-51-09] [FATAL] 0x401570 exceptionLogger()
[18-04-2019_20-51-09] [FATAL] 0xb84cb0 MPEGaction::MPEGaction()
[18-04-2019_20-51-09] [FATAL] 0xd2c110 void std::iter_swap<__gnu_cxx::__normal_iterator<OpenXcom::ScriptProcData*, std::vector<OpenXcom::ScriptProcData, std::allocator<OpenXcom::ScriptProcData> > >, __gnu_cxx::__normal_iterator<OpenXcom::ScriptProcData*, std::vector<OpenXcom::ScriptProcData, std::allocator<OpenXcom::ScriptProcData> > > >(__gnu_cxx::__normal_iterator<OpenXcom::ScriptProcData*, std::vector<OpenXcom::ScriptProcData, std::allocator<OpenXcom::ScriptProcData> > >, __gnu_cxx::__normal_iterator<OpenXcom::ScriptProcData*, std::vector<OpenXcom::ScriptProcData, std::allocator<OpenXcom::ScriptProcData> > >)
[18-04-2019_20-51-09] [FATAL] 0xd31090 OpenXcom::ScriptGlobal::addTagType<OpenXcom::ScriptTag<OpenXcom::RuleItem, unsigned char> >()::{lambda(unsigned long long)#1}::_FUN(unsigned long long)
[18-04-2019_20-51-09] [FATAL] 0x649170 OpenXcom::Mod::getRegion(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, bool) const
[18-04-2019_20-51-09] [FATAL] 0x43cbd0 OpenXcom::GeoscapeState::processCommand(OpenXcom::RuleMissionScript*)
[18-04-2019_20-51-09] [FATAL] 0x43f6b0 OpenXcom::GeoscapeState::determineAlienMissions()
[18-04-2019_20-51-09] [FATAL] 0x4401c0 OpenXcom::GeoscapeState::time1Month()
[18-04-2019_20-51-09] [FATAL] 0x440440 OpenXcom::GeoscapeState::timeAdvance()
[18-04-2019_20-51-09] [FATAL] 0x7d8f40 OpenXcom::Timer::think(OpenXcom::State*, OpenXcom::Surface*)
[18-04-2019_20-51-09] [FATAL] 0x80afb0 OpenXcom::Game::run()
[18-04-2019_20-51-09] [FATAL] 0x4016b0 SDL_main
[18-04-2019_20-51-09] [FATAL] 0x9de110 console_main
[18-04-2019_20-51-09] [FATAL] 0x9de230 WinMain
[18-04-2019_20-51-09] [FATAL] ??
[18-04-2019_20-51-09] [FATAL] ??
[18-04-2019_20-51-09] [FATAL] 0x7ff8b89e8350 BaseThreadInitThunk
[18-04-2019_20-51-09] [FATAL] 0x7ff8bb2d7090 RtlUserThreadStart
[18-04-2019_20-51-19] [FATAL] OpenXcom has crashed: Region REGION_HULK_SITES not found

ohartenstein23 @ohartenstein23

Thanks for the report, I'll make sure it gets fixed soon. We have a number of bugs with the 019 release due to the globe changes, so likely 020 will come out soon just to patch up these problems.

Guest @guest

Sorry if this had already been discovered, but i am having a problem. In the battlescape the game will sometimes just switch which unit I have selected. It was not a big problem at first because it only did it once or twice ever now and then but i just had to quit playing because it was just cycling rapidly through all my units while my hands where off the mouse and keyboard completely. Please let me know if this is a bug or if it's on my end.

ohartenstein23 @ohartenstein23

I've never heard of that happening before, and is likely a problem with one of your input devices.

Guest @guest

Yes you are right, I tested it on a vanilla game and i had the same problem. However, i never had this problem when i played on normal OpenXcom. My mouse also works fine so if you know what it could be i would appreciate you telling me. If not, don't worry about it and thanks for the reply.

ohartenstein23 @ohartenstein23

I've had soldiers cycle somewhat like that when using the scroll feature on a laptop touchpad, that's one place to start looking. Maybe a sticky TAB key could be another.

You might also try re-installing OXCE, maybe something went wrong with your installation.

Guest @guest

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Elite_krew @elite-krew

10/10 Would burn the heretic again

ohartenstein23 @ohartenstein23

Bugs are fixed, 019 is live for real this time!

ohartenstein23 @ohartenstein23

I just took down the 019 download due to some crash-causing bugs. I'll re-upload the release when they are fixed.

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jritter @jritter

Hey, been really enjoying this mod, it's been everything I never knew I was looking for. I'm about 2 years in on my first playthrough, I think I have all the techs (just research final order) I can possibly get and I'm wondering if there is an end to the mod, like the final mission in vanilla, and if so how to trigger it, or is it still WIP? Thanks!

ohartenstein23 @ohartenstein23

Hi jritter, glad you're enjoying it! There is an end made very similar to vanilla UFO - you have to build the "Chapter Army" if you're playing marines and use it to go to the final mission, or any craft if you're playing as the Imperial Guard.

If you're having trouble getting to the point of building the "Chapter Army" craft, I think it depends on researching a number of Chaos Craft. You do that by interrogating "engineer" enemies that have information about their craft. In the next version we're planning on making this a bit more straightforward.

jritter @jritter

I assume you mean the 1st company when you say chapter army?

ohartenstein23 @ohartenstein23

Yes, the 1st Company.