Mothership - Starter guide
What is Mothership?
Mothership is a sci-fi horror tabletop RPG designed by Sean McCoy and published by Tuesday Knight Games. You play as crew members aboard spaceships and stations in a grim, unforgiving universe where the odds are stacked against you. Think less Star Trek, more Alien or Event Horizon. The tone is tense, the stakes are high, and survival is never guaranteed.
This is not a game about being heroes. It's a game about people doing their best in terrible situations - and sometimes not making it.
How does the system work?
Mothership uses a percentile system: you roll two ten-sided dice and try to roll equal to or under your relevant stat. Characters have four core stats - Strength, Speed, Intellect, and Combat - alongside a set of derived saves (Body, Fear, and Sanity). Skills are tiered into Trained, Expert, and Master, and each grants a meaningful bonus to your roll.
The heart of the system is the Stress and Panic mechanic. Stress accumulates through frightening encounters, failed rolls, and the general horror of the situation. When it gets too high, characters have to make Panic checks - and if they fail, they roll on the Panic table. The results range from freezing up, to fleeing, to something much worse. It's elegant, uncomfortable, and does exactly what horror needs: it makes players feel vulnerable without taking control away entirely.
Character creation is deliberately fast. You can build a functional crew member in under ten minutes. Four classes are available - Teamster, Scientist, Android, and Marine - each with a different stat spread and skill set.
What do you need to get started?
The 1st edition of Mothership comes as a boxed set from Tuesday Knight Games, containing:
- The Player's Survival Guide (the core rules for players)
- The Warden's Operations Manual (the GM's toolkit, including monster creation, station generation, and horror advice)
- The Shipbreaker's Toolkit (a referee screen with useful tables)
- A starter adventure to get you playing immediately
Everything you need is in that box. There is no separate "core rulebook" - the split between player and Warden material is intentional and keeps things tight.
The 0e version of Mothership (an earlier, slimmer edition) is available for free online, and while it differs from 1e in some ways, it gives you a solid sense of the game's DNA before you commit.
Who is this game for?
Mothership is a great fit if you want horror-first storytelling in a sci-fi setting. The system rewards player ingenuity and resource management over character power - this is an OSR-adjacent game at heart. If your group enjoys tension, meaningful decisions, and the occasional brutal loss, Mothership will deliver.
It works best with groups willing to lean into atmosphere and prepared for characters to die. If your players prefer long-term character investment or systems that protect them from sudden failure, Mothership may feel brutal.
It handles: survival horror, exploration, crew-based drama, claustrophobic tension. It struggles with: extended campaign play over many sessions, political intrigue, large-scale heroics.
How does it differ from other systems?
Compared to Dungeons & Dragons, Mothership is dramatically leaner. There are no hit points in the traditional sense - wounds are specific, recovery is slow, and combat is dangerous for everyone at the table. Where D&D often rewards persistence, Mothership rewards caution.
Compared to Call of Cthulhu, which shares the horror DNA, Mothership is faster and more focused on physical peril alongside psychological threat. The sci-fi setting also opens up very different narrative territory.
Where do you begin?
- Read the Player's Survival Guide cover to cover - it's short enough to do in an evening.
- Have players build characters together at the table during session zero. It's fast and generates good conversation about the setting.
- Run the starter adventure included in the box before attempting to build your own scenarios.
- Once you're comfortable, the Warden's Operations Manual has excellent tools for creating locations, threats, and encounters.
For external resources: the Mothership subreddit (r/mothershiprpg) is active and welcoming. The Tuesday Knight Games website hosts additional free modules and community content. YouTube has several actual plays and intro videos - searching "Mothership RPG actual play" will get you started quickly.
Recommended products
The 1st Edition Boxed Set is the obvious starting point - it's a complete, well-designed package that gives you everything at once.
Beyond that, Mothership shines with good adventure modules. Dead Planet is one of the most acclaimed (a dark, brutal dungeon crawl in space), and A Pound of Flesh offers a sprawling space station to explore with its own sandbox structure. Gradient Descent is a longer, more complex delve for groups ready to go deeper.
If you want to expand the toolkit, the community has produced a large amount of third-party content - much of it high quality and built around the same tight design philosophy.