Call of Cthulhu vs R'lyehwatch

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

	Call of Cthulhu	R'lyehwatch
Genre	Horror, Modern	Horror, Modern
Play Style	Investigation, Deadly, One-Shot Friendly, Atmospheric, Roleplay-Heavy, Mystery, Horror, Corruption, Skill-Based	Rules-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 Mechanic	Roll d100 equal to or under your skill percentage. Success tiers at half (Hard) and one-fifth (Extreme) of the skill value. Bonus and penalty dice adjust the tens digit. Failed rolls can be pushed for a second attempt at greater risk.	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.
Dice	d100	d6 dice pool
Complexity	Medium	Very Low
Accessibility	Medium	High
Community	High	Low
License	Chaosium Fan Material Policy	Proprietary; third-party license and SRD permit derivative works
Cost	$$	$
Publisher	Chaosium	Hedgemaze Press / Third Chair Games
Year	2014	2023
Best For	Investigation-driven horror where combat is deadly and sanity is fragile. Great for one-shots.	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.
Highlights	Sanity system mechanically reinforces horror tone. Intuitive percentile skill system with tiered success levels. One of the largest published scenario libraries in the hobby.	Three 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.
Considerations	Chase rules add complexity with limited payoff, 46-skill list requires point allocation across multiple categories, sanity spiral can remove player agency in extended campaigns	Mechanically 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.