Cthulhu Dice

Steve Jackson Games ultra-quick 2-6 player dice game (Steve Jackson, 2010) — one custom 12-sided die + sanity tokens. Roll to steal sanity from opponents; last sane player wins. ~15 min, ~$10 retail. Iconic Lovecraftian party filler.

~15 min🌤indoor

What is Cthulhu Dice?

Cthulhu Dice is an ultra-quick lightweight party dice game designed by Steve Jackson + published by Steve Jackson Games (SJG), released 2010. 2-6 players; ~15 min play; ~$10 MSRP. Uses one 12-sided die with symbols instead of numbers (Yellow Sign, Elder Sign, Cthulhu, Tentacle, Eye of Horus). Each player starts with 3 Sanity tokens (glass beads). On your turn: pick a target player, roll the die once, resolve symbol effect (Yellow Sign = target loses 1 Sanity to you; Elder Sign = you gain 1 Sanity from pool; Cthulhu = everyone loses Sanity; Tentacle = swap Sanity totals; Eye of Horus = target loses 1 to pool). When you're reduced to 0 Sanity, you become 'insane' — still play, but win only if all other insane players joined by everyone becoming insane in same round (last-sane-wins otherwise). Iconic Lovecraftian light party game; often used as filler between heavier games. Tiny footprint (fits in shirt pocket). Rules learnable in 60 seconds.

Quick facts

Category

Dice Games

Type

Mixed

Players

2–6

Duration

~15 min

Where played

indoor

Country of origin

🇺🇸 United States

Estimated origin

Released 2010 by Steve Jackson Games

Olympic

No

Popularity

regional

How it works

Objective

Be the last player with Sanity remaining (or if all players go insane simultaneously, all insane players win).

Match structure

Rounds continue until only one player has Sanity remaining (or all go insane).

Rules

Basic rules

  • Roll die at chosen target on your turn

    Pick any other player as target, roll the 12-sided die, resolve symbol effect.

  • Yellow Sign / Elder Sign / Cthulhu / Tentacle / Eye

    Each face has different Sanity-transfer effect.

  • Reduce all opponents to 0 Sanity to win

    Last sane player wins; or all players go insane in same round = all insane players win.

Advanced rules

  • Insane player still plays

    Insane players continue rolling on turns but hoping others also go insane.

  • Sanity pool (Elder Sign)

    Central pool that pays out on Elder Sign rolls.

Scoring

No score — Sanity survival based.

ActionPoints
Sanity tokenTracked personally

Win condition · Last player with Sanity wins; or all-insane simultaneous = all insane players share win.

Equipment

  • 1 custom 12-sided die

    Symbol die: Yellow Sign, Elder Sign, Cthulhu, Tentacle, Eye of Horus faces.

  • Sanity tokens (glass beads)

    3 per player at start.

  • Tiny rulebook + carry pouch

    Fits in shirt pocket.

Positions & roles

  • Cthulhu Cultist

    ×1

    Solo player attempting to steal others' Sanity.

Officiating

No officials.

  • Group consensus

Penalties & fouls

Penalties

  • Losing all Sanity

    Become insane; can only win if all other players also insane.

Strategies

  • Target leader with high Sanity

    Focus roll on player with most Sanity to prevent runaway leader.

  • Tentacle swap timing

    If Tentacle rolls, use to swap Sanity with player whose total helps you most.

Terminology

Yellow Sign
Face — target loses 1 Sanity to you
Elder Sign
Face — you gain 1 Sanity from pool
Cthulhu
Face — everyone loses Sanity
Tentacle
Face — swap Sanity totals with target
Eye of Horus
Face — target loses 1 to pool
Sanity
Player HP-equivalent tokens

Major competitions

  • Not applicable — party filler game

    n/a · n/a · since 2010

Where it is played

Governing bodies

  • Steve Jackson Games

    Founded 1980 · Austin, Texas

Famous names & records

Famous athletes

  • Steve Jackson (designer)

Records

  • Released 2010 by SJG

    Steve Jackson GamesReleased 2010; still in print + widely stocked (2010)

  • Signature quick-filler dice game

    SJGConsidered signature 'quick filler' Lovecraftian party dice game (2015)

Learn this sport

beginner

  1. 1

    First 3-player game

    Learn 5 die faces in one game (~10 min).

intermediate

  1. 1

    5-6 player chaos

    Multi-player games have more chaos + more insane-simultaneous-win potential.

Frequently asked

How long is one game of Cthulhu Dice?+

10-15 minutes typically. Designed as a quick filler between larger games or a light party game.

Can I win after going insane?+

Yes — if all players go insane in the same round, all insane players share the win. So 'trolling' a slow-to-die opponent by inducing simultaneous insanity is a legitimate strategy.

Sources & provenance

Last verified 2026-08-29.verified