Mothership RPG

Officially Mothership Sci-Fi Horror RPG

SCI-FI HORROR TABLETOP RPG (Sean McCoy, 2018; 1E boxed set 2023) — LEAN d100 percentile system for space-horror in tradition of ALIEN + EVENT HORIZON + DEAD SPACE. Player characters are BLUE-COLLAR SPACE WORKERS (TEAMSTERS, SCIENTISTS, MARINES, ANDROIDS) trying to SURVIVE hazardous space encounters. Signature elements: LEAN + FAST RULES (~10 min learn), heavy STRESS + PANIC mechanics, high LETHALITY, IMPROVISATIONAL GM design. Multiple ENNIE AWARDS + huge indie hit; Boxed Set 1E won 2023 ORIGINS. Setting-agnostic — GM crafts own space universe.

~180 min🌤both

Quick facts

Category

Tabletop Role-Playing

Type

Team sport

Players

3–6

Duration

~180 min

Where played

both

Country of origin

🇺🇸 United States

Estimated origin

Designed 2018 by SEAN MCCOY as short OSR-inspired sci-fi horror system (0E released free on itch.io); 1E BOXED SET released 2023 after successful Kickstarter (raised $1.4M); published by TUESDAY KNIGHT GAMES; won multiple ENNIE + ORIGINS awards 2023-2024; huge indie hit inspired by ALIEN + EVENT HORIZON + PROMETHEUS + DEAD SPACE aesthetic; sparked wave of low-fi sci-fi horror TTRPGs.

Olympic

No

Popularity

regional

How it works

Objective

SURVIVE life-threatening space-horror scenarios; NOT beat monsters — RUN, HIDE, IMPROVISE, or DIE.

Rules

Basic rules

  • d100 UNDER STAT SYSTEM: roll 2×d10 as percentile; roll UNDER your STAT (Strength, Speed, Intellect, Combat) to succeed

    Signature roll-under-stat percentile.

  • 4 CLASSES: TEAMSTER (blue-collar), SCIENTIST (researcher), MARINE (combat), ANDROID (synthetic)

    Signature 4-class system.

  • STRESS + PANIC: accumulate STRESS from horror + injury; roll for PANIC when stressed — panic effects escalate (freeze, hallucinate, self-harm, cardiac arrest)

    Signature stress + panic escalation.

  • HIGH LETHALITY: fights are deadly + rare; encourage RUNNING + HIDING + SNEAKING + IMPROVISING

    Signature deadly-combat design philosophy.

  • MINIMAL EQUIPMENT: characters start with $0-500 credits + basic gear; scarcity is horror element

    Signature minimal-gear starting inventory.

  • SETTING-AGNOSTIC: no default world; each GM crafts own space universe or uses PUBLISHED MODULES (Dead Planet, Gradient Descent, A Pound of Flesh, Desert Moon of Karth)

    Signature setting-agnostic + modules.

  • FAST CHARACTER CREATION: 5-10 min per character (vs. 30-60 min for D&D)

    Signature rapid character creation.

Scoring

No score; survival + progression via credits + XP.

Win condition · Party survives + completes contract or module; no formal winning.

Equipment

  • MOTHERSHIP PLAYER SURVIVAL GUIDE (character creation + core rules)

    Signature Player Survival Guide (Book 1).

  • WARDEN'S OPERATIONS MANUAL (GM guide + tools)

    Signature Warden's Manual (Book 2).

  • SHIPBREAKER'S TOOLKIT (space ship + starship rules)

    Signature Shipbreaker Toolkit (Book 3).

  • UNCONFIRMED CONTACT REPORTS (bestiary + adversaries)

    Signature UCR bestiary (Book 4).

  • PERCENTILE DICE: 2×d10 (or d100)

    Standard percentile dice.

  • CHARACTER SHEETS + PANIC SHEETS + MODULES

    Standard sheets + modules.

Terminology

Warden
Mothership's term for the GM (Game Master).
Stress + Panic
Core horror mechanic — stress accumulates, panic rolls trigger effects.
MoSh
Fan abbreviation for Mothership.
Module
Published pre-made adventure (Dead Planet, Gradient Descent, etc.).
Contract
PC's job/mission — often survival-oriented.

Where it is played

Governing bodies

  • Tuesday Knight Games (publisher + rights)

    Founded 2018 · Nashville, TN, USA

Sources & provenance

Last verified 2026-08-28.verified