Provably fair horror demo

12ga Roulette

A grim chamber game with fair-odds payouts, escalating multipliers, and a client-side seed verifier.

Presentation mode

Full grim keeps the horror framing. CW wording softens self-harm language.

How it works Back to tools

Briefing

Three choices. Fair odds. Real multipliers.

Each shell is sealed by an HMAC-SHA256 shuffle the client can replay in your browser. Every action is fair-EV; the multiplier grows by exactly the inverse of its survival probability.

Stack (self) Bet next shell is blank
Press (opponent) Bet next shell is live
Cash out Lock in current multiplier
Verifier Replays HMAC in your browser

New here? Read the rules and math →

Setup

Choose how cruel the cylinder gets.

Pick a volatility profile, lock in your client seed, and start. The server commits a hash of its seed up front and reveals the full seed once the round ends.

Higher shell counts permit deeper stacks and bigger ceilings (12-shell / 2-live can reach ×60+ before a final press).

The server uses your seed plus a nonce to build the chamber order. Same seed + nonce = same chamber.

Round nonce 0
Client seed mirror —

In play

The chamber is live.

Bet 1.00 · Mult ×1.00

Start a round to spin up the chamber.

Current chamber — No round loaded
Awaiting input

Pick a volatility, set a seed, and start a round.

If you stack — Blank survives, live busts
If you press — Live wins, blank busts
Cash out now ×0.97 No risk, ends round

Aftermath

The chamber goes still.

Review the result, reveal the sealed seed, and verify that the chamber was honestly built — entirely in your browser.