Mothership RPG
Officially Mothership Sci-Fi Horror RPG
SCI-FI HORROR TABLETOP RPG by SEAN MCCOY (TUESDAY KNIGHT GAMES, 2018 zine → 2023 hardcover). Inspired by ALIEN, EVENT HORIZON, DEAD SPACE. PC-CENTRIC + HIGH-LETHALITY: characters are BLUE-COLLAR SPACE WORKERS (Teamsters, Marines, Scientists, Androids) facing existential horrors. D% (percentile) mechanic — roll UNDER a stat + skill; SAVE vs. FEAR, STRESS accumulates, PANIC checks compound. Runs from a THIN A5-size RULEBOOK (formerly ZINE); praised for BRUTAL SIMPLICITY + PLAYER-FACING DESIGN.
Quick facts
Category
Tabletop Role-Playing
Type
Team sport
Players
3–6
Duration
~180 min
Where played
indoor
Country of origin
🇺🇸 United States
Estimated origin
Original zine 1st edition by Sean McCoy 2018; won 5 ENnie Awards; 2020-2023 Kickstarter for hardcover 1E raised $1.4M (top-funded RPG Kickstarter of 2020); 2023 hardcover 1E boxed set + module lineup 'Deep Space Signals'.
Olympic
No
Popularity
regional
How it works
Objective
Cooperative narrative — survive sci-fi horror scenarios; role-play character choices; often, the goal is JUST TO SURVIVE.
Rules
Basic rules
STATS (0-100): STRENGTH, SPEED, INTELLECT, COMBAT; SAVES: SANITY, FEAR, BODY, ARMOR
Signature 4 stats + 4 saves.
D% MECHANIC: roll d100 UNDER (Stat + Skill) = success; 01-05 = crit; 96-00 = fumble
Signature roll-under d%.
CLASSES: TEAMSTER (blue-collar generalist), MARINE (combat specialist), SCIENTIST (research + tech), ANDROID (synthetic — starts with permanent damage + Stress immunity trade-off)
Signature 4-class system.
STRESS: accumulates when scared/hurt; when stress > save threshold, PANIC CHECK: d20 + stress vs. Panic table (worst = PSYCHIC BREAK)
Signature stress + panic cycle.
LOW HP (4-8 HP average) → PCs DIE EASILY; even lucky rolls can end a character; game explicitly designed for BRUTAL horror stakes
Signature high-lethality design.
SHIPS + JOBS: PCs are BROKE contractors owing money; take dangerous jobs; corporate powers + ancient evil menace stories
Signature blue-collar sci-fi tone.
WARDEN (GM) tools: bestiary, ship generators, encounter tables, session zero horror-lines/veils
Signature GM support toolkit.
Scoring
Narrative RPG — no traditional scoring; PC survival + mission completion + character-arc satisfaction.
Win condition · Cooperative narrative outcome; often survival itself is the win.
Equipment
MOTHERSHIP CORE RULEBOOK (2023 hardcover, ~144 pp) OR original zine (2018)
Signature core rules.
PLAYER CHARACTER SHEETS: Teamster / Marine / Scientist / Android (4 classes)
Signature 4 character classes.
d100 (2× d10 or percentile die)
Signature d% system.
d5 + d10 + d20 for damage + panic checks
Standard supporting dice.
MODULES: 'Dead Planet', 'Another Bug Hunt', 'Pound of Flesh', 'Gradient Descent' — self-contained sci-fi horror scenarios
Signature module library.
PENCILS + CHARACTER SHEETS + battlemap (optional)
Standard RPG paraphernalia.
Terminology
- Warden
- The Game Master (GM) in Mothership terminology.
- Panic check
- Roll d20 + stress vs. panic table when PC's stress > save.
- Save
- One of four defensive stats: Sanity, Fear, Body, Armor.
- Teamster / Marine / Scientist / Android
- The 4 PC classes.
- TKG
- Tuesday Knight Games — publisher.
Major competitions
GenCon / PAX Unplugged / RPG-conventions Mothership one-shots
annual · USA + global convention circuit · since 2018
ENnie Awards (Mothership won 5, 2019+)
annual · GenCon, Indianapolis · since 2001
Where it is played
Governing bodies
Tuesday Knight Games (publisher)
Founded 2011 · Austin, TX, USA
Famous names & records
Famous athletes
- Sean McCoy (US, designer/founder Tuesday Knight Games)
- Tuesday Knight Games team (Fiona Maeve Geist, Luke Gearing, etc.)
- Modular RPG designers in the Mothership 3rd-party ecosystem (Zzarchov Kowolski, Kellermann, Chris Airiau)
Sources & provenance
- Wikipedia — Mothership (RPG)— Wikipedia
- Tuesday Knight Games— TKG