Summary
RimWorldis a popular“story simulator” game, a genre of simulation games designed to create emergent stories based on the player’s behavior and intelligent use of not-so-random events. By default,RimWorldsees players managing a group of survivors who must turn the site of their crash landing into a prosperous colony or die trying.
SinceRimWorldis ultimately a system for creating stories, much of the game can be changed without losing its identity. The player’s colonists might as well be the inhabitants of a space station or astronauts trying to survive on a hostile planet that has never seen life before. Many of thebest mods available forRimWorlddo just that.

1Knights Of The Outer Rim
Star Wars In RimWorld
Knights of the Outer Rimis a total conversion mod forRimWorldbased on theStar Warssetting, and in particular on theKnights of the Old RepublicRPG series. This mod has only been in development since early 2023, but it has already amassed an impressive number of features.
Knights of the Outer Rimchanges the game to resemble theStar Warsuniverse in every way by adding appropriate alien races, clothes and weapons, droids, and force powers. In the future, the game will receive new content focused on the story, with setting-appropriate quests and a progression system to unlock force powers.

2Phonicmas' Warhammer 40.000
Warhammer 40K In RimWorld
Warhammer 40Kmods seem to be everywhere, andRimWorldis no exception. The dystopic sci-fi series might have had its start in miniature-based war games, but it has since taken over video games. Warhammer 40.000by Phonicmas isn’t themost popular total conversion modforRimWorld, but it’s impressive, especially for a fan project.
Warhammer 40.000 is divided into a few sub-mods, some of which are optional modules, and some are required for anyone who owns the dedicated DLC, with most falling somewhere in between. Warhammer 40.000 – Genes, for example, requires the Genes DLC forRimWorld, but it also adds new elements based onWarhammerlore.

3Rimstation 13 - The Quest For Spess
Space Station 13 In RimWorld
Nowadays,Space Station 13isn’t a very popular name on the internet, but it used to be all the rage some ten or twenty years ago.Space Station 13is a multiplayer RPG where mostplayers actually role-play. It was probably the largest open-source game of its day. And now it’s one of the biggest total conversion mods forRimWorld.
Rimstation 13 - The Quest For Spessdoesn’t adapt the game ofSpace Station 13intoRimWorld, as it remains squarely single-player, but it adapts the setting, the titular space station. A weird choice, considering that the most memorable feature ofSpace Station 13was its mod support. Every server would have its own setting and rules. Rimstation 13 also tries to bring the emergent multiplayer gameplay of the classic game to this single-player experience, with interesting results.

4TiberiumRim
Command & Conquer Setting In RimWorld
TiberiumRimis the kind of mod no one would expect. It’s a mix of the setting of the1990s strategy game seriesCommand & Conquerwith the gameplay and story premise ofRimWorld.Command & Conquerisn’t really known for its story or setting, but if the success of this mod is any indication, maybe it should.
TiberiumRimtransforms the setting ofRimWorldinto that of the classic RTS series, but it also adds a new storyline about Tiberium, the mysterious alien material that caused the world ofCommand & Conquerto fall into constant war. The mod also adds new weapons, clothing, factions, buildings, and so on.

5MarsX
Colonizing Mars In RimWorld
MarsXis a space colony mod set on the planet Mars. It’s noticeable for being one of the first mods forRimWorldto become extremely popular. It’s also one of the largest mods that isn’t inspired or dedicated entirely to recreating a different IP insideRimWorld. Instead, players are tasked to create a stable human dwelling on the incredibly hostile surface of the red planet.
MarsXhasn’t been updated in a while, as the latest version was released in 2017. Version 4.0 seems to be right around the corner, at least according to the Steam Workshop page, but it’s hard to know how old those promises are. As far as fans are concerned, MarsX V3is a complete game, so interested players should probably not wait for an update.

6Rim-Effect
Mass Effect In RimWorld
Rim-Effectis an enormous mod dedicated to transportingRimWorldinto theMass Effectuniverse. Some of the mod’s many changes and additions include new alien races, items and buildings, factions, and objectives inspired byMass Effect. Likemany mods of its size,Rim-Effectis divided into modules to make the experience easier to customize.
Some of the more interesting additions that come with Rim-Effectare the new skills thatRimWorldcharacters can learn. These include many powers inspired by theMass Effectgames, including the series’ classic Tech and Biotic abilities. One issue the mod has recently encountered is that, perhaps after growing larger than anticipated, its dedicated wiki became outdated and is now offline. Navigating this massive mod just got a lot harder.

7Call Of Cthulhu - Rim Of Madness
Eldritch Horror In RimWorld
Most of the popular mods forRimWorldare exactly what one would expect:simple tweaks to the base game, science fiction series-inspired total conversions, or new characters and events. Occasionally, a mod will wildly change how the space colony simulator works. But all those mods are still rooted in the same genre. Call of Cthulhu - Rim of Madnessis not that kind of mod. For one, it’s not sci-fi, even if some of theRimWorldinfluence remains.
Another weird thing about Call of Cthulhu - Rim of Madness is its objective. This mod doesn’t just add cultists and monsters from the classic eldritch horror catalog. Instead, it tries to turn this wacky, sometimes funny story generator into a horror experience. That might be unusual, but if the fans’ opinion is anything to go by, this mix turned out to be a winning formula.
