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Mothership vs R'lyehwatch

Compare Mothership and R'lyehwatch side by side. See differences in complexity, dice, genre, cost, and more.

MothershipR'lyehwatch
GenreScifi, HorrorHorror, Modern
Play StyleRules-Light, Deadly, One-Shot Friendly, Survival, Atmospheric, Low-Prep, Cinematic, Fast-PacedRules-Light, Horror, Comedy, Beginner-Friendly, One-Shot Friendly, Fast Sessions, Cinematic, Player-Only Rolls, Theater of the Mind, Atmospheric, Weird, Random Tables, GM-Friendly, Hackable
Core MechanicRoll d100 under stat/skill. Stress and panic mechanics escalate tension.Players roll a pool of 1–3 d6s against a target difficulty (4 for easy, 5 for average, 6 for hard). Every challenge starts with 1 die — add a second if the challenge matches the character's stat (Agile, Brawny, or Crafty), and a third if their role applies (The Veteran, Rookie, Medic, Gizmo, Detective, or Weirdo). Success means at least one die meets or beats the difficulty. Players spend luck tokens to invoke a perk and lower the difficulty by 1, and recover luck by letting their quirk cause a problem (raising the difficulty by 1). Grit tokens absorb failure consequences; a character who runs out of grit is removed from the scene. The referee never rolls dice during a challenge — they choose the stat and difficulty, then narrate the outcome. Extended challenges (chases, fights, infiltration) deplete a shared pool of effort tokens, one per success.
Diced100d6 dice pool
ComplexityLowVery Low
AccessibilityHighHigh
CommunityMediumLow
License3rd Party LicenseProprietary; third-party license and SRD permit derivative works
Cost$$
PublisherTuesday Knight GamesHedgemaze Press / Third Chair Games
Year20222023
Best ForTerrifying sci-fi horror one-shots and short campaigns. Panic table creates unforgettable moments.Groups who want a quick, comedic cosmic-horror RPG that pairs Baywatch-style melodrama with the Cthulhu Mythos. Tuned for pickup play and 2-4 hour sessions, with three tonal modes (Casual, Standard, Horror) that retune lethality without changing the core rules.
HighlightsRules-light, well-regarded module library, panic system creates mechanical tensionThree difficulty targets and a 1–3 d6 dice pool make up the entire resolution system. Three tonal modes (Casual, Standard, Horror) adjust grit recovery rate, retuning the same rules from sitcom-style play to deadly survival horror without changing any mechanics. All heroes share a universal Slow Motion quirk — narrating a slow-motion moment recovers a luck token but raises the current challenge's difficulty. Adventure generator combines random Objective, Location, and Complication tables for pickup scenarios; also includes an Elder Gods & Cults table, a Monster Maker, and a mapped Sunset Hills setting.
ConsiderationsPanic table can cascade and end sessions abruptly, limited long-campaign support in core rules, stress mechanics can feel repetitive over extended playMechanically minimal — no advancement track beyond optional luck and grit cap increases, no gear lists, no tactical combat structure. Pacing assumes 2–4 hour sessions rather than multi-arc campaigns. Setting is anchored to Sunset Hills, California; running the game elsewhere requires reskinning the included cult, NPC, and location tables. Three difficulty values and a maximum 3-die pool give coarse resolution — granular skill differentiation is not the design.