A crash game is the simplest casino game invented in the internet era. A multiplier starts at 1.00x and climbs. You cash out whenever you like and win your stake times the multiplier. At a random moment the multiplier "crashes", and anyone still in loses. Rounds last seconds, everyone in the room plays the same round and the whole thing runs in a browser tab, much like an .io game. Here is where the format came from and what its maths really says.
Where crash games came from
Most accounts trace the format to MoneyPot, a Bitcoin game launched in 2014 on the BitcoinTalk forum by a Canadian developer usually named as Eric Springer. It was sold the next year and renamed Bustabit, which is still running. Crypto casinos copied the format, and in 2019 the studio Spribe released Aviator, which replaced the line graph with a small plane and brought crash games to mainstream licensed casinos in many countries. Today most crypto casinos have their own crash game, often with a rocket.
The multiplier maths
In a typical crash game, the crash point is set so that the chance of reaching any multiplier x is roughly (1 − house edge) ÷ x. With a 1 percent house edge:
| Cash out at | Chance of reaching it | Expected return per 1 unit |
|---|---|---|
| 1.5x | about 66% | 0.99 |
| 2x | about 49.5% | 0.99 |
| 10x | about 9.9% | 0.99 |
| 100x | about 0.99% | 0.99 |
The last column is the key. Whatever target you choose, the expected return is the same: 0.99 of your stake, because the chance of reaching a multiplier falls exactly as fast as the multiplier rises. Waiting longer only changes the volatility. Low targets win often and small; high targets win rarely and big. No cash-out strategy changes the long-run result, and martingale-style systems that double after losses only raise the risk of a large loss. Real games vary: some add a small chance of an instant crash at 1.00x, and Aviator is reported to pay out around 97 percent.
What "provably fair" means
Online players cannot see a casino's random number generator, so crypto casinos use cryptography to show that results were not changed after bets were placed. The common scheme works like this:
- Commit. Before you play, the casino generates a secret server seed and shows you only its hash, for example its SHA-256 fingerprint. The hash commits the casino to that seed without revealing it.
- Mix in the player. You supply, or are given, a client seed, and each round has a counter called a nonce.
- Compute. The result is derived from all three, typically with HMAC-SHA256, and converted into a crash point, card or Plinko path.
- Reveal and verify. Later the casino reveals the server seed. You check that it matches the hash you saw and recompute each result yourself.
Bustabit uses a variation: a long chain of hashes generated in advance and used in reverse order, so each game's hash proves the previous one, combined with a public value fixed before the chain was used. Either way, the principle is a cryptographic commitment.
What provably fair does not prove
Provably fair proves that a result was fixed in advance and not tampered with. It does not prove that the game is a good bet: the house edge is built into the formula that turns the hash into a result, in plain sight. It does not prove the operator is licensed, solvent or will pay withdrawals. And it only helps if someone actually checks. Licensed casinos rely instead on independent testing laboratories and regulators, which audit the RNG and game maths.
Crash, Plinko and the browser-game look
Crash games belong to a wider family of crypto-casino "originals", including Plinko, dice and mines, that look like simple browser games and use the same provably fair system. The Plinko version is explained in the physics and RNG behind slots and Plinko. And the reason crash rounds feel so compelling, the near-miss of cashing out just before or after the crash, is a design pattern we cover in variable rewards.
