Cthulhu Hack

Cthulhu Hack is a rules-lite investigative horror game that pares Lovecraftian mystery down to d20 saves, usage dice, and mounting pressure. It keeps the focus on dread, bad options, and dangerous curiosity, making it a strong pick for one-shots or short campaigns where atmosphere matters more than crunchy procedure.

At-a-glance

Cosmic Horror • Needs GM • 2/5 complexity • One-shot friendly • Low prep

Decision Tags:
Low PrepOne-Shot Friendly
Cthulhu Hack

Cthulhu Hack takes the frame of Mythos investigation and strips it to the essentials: scared people, dangerous clues, and resource dice that tell you exactly when control starts slipping away. It is built for tables that want fast, tense sessions where every push for more information feels risky.

Theme and Setting

The game lives comfortably in Lovecraftian territory, but it does not require dense setting mastery to work. You can drop investigators into a rural disappearance, a cursed manuscript hunt, or a city cult mystery and get to the pressure quickly. The mood is anxious and human-scaled rather than pulp-heroic.

How Play Feels

Play moves fast because the rules get out of the way early. d20 saves resolve dangerous action, while usage dice turn stress, dwindling supplies, and fraying safety into visible tension at the table. That makes discovery feel costly in a satisfying way: clues arrive, but so does the sense that the investigators are spending themselves to survive.

What Makes It Distinct

What makes Cthulhu Hack stand out is how little machinery it needs to produce dread. Where heavier investigative games can lean on skill lists, subsystems, or scenario structure, this one keeps attention on pacing, consequence, and the moment players decide whether to dig deeper. It is especially good when you want Mythos horror that teaches quickly and lands hard.

Where It May Not Fit

It is a weak fit if your group wants detailed tactical combat, lots of character-build differentiation, or an extended campaign with many mechanical levers to pull. The game is intentionally sparse, and that sparseness is its identity.

Decision guide

What this game is about

Key facts
Players
2-5 players + GM
Session
120-180 minutes
Prep
Low
Play profile
Complexity
2/5
New GM Fit
4/5
Roleplay Focus
4/5
Combat Focus
1/5
Tactical Depth
1/5
Campaign Depth
2/5
Who it suits
Best for
Tables that want solving problems and following clues to matterGroups that want tension, danger, and unease to stay active at the tableOne-shots or short arcs that need to establish dread quickly
Avoid if
You want denser mechanical crunch or build complexityYou want combat and action to drive most of the sessionYou want a longer campaign with lots of mechanical progression

A strong fit for groups that want solving problems and following clues to matter, with rules-lite investigation driving the tension.

Agent data

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