Anatomy of a crash round: from seed to cash-out

The round exists before anyone bets on it. A server seed is generated and its hash published, which fixes the crash point for that round while keeping it hidden. Nothing that happens during the round can move it.

This is the same commitment scheme every provably-fair game uses, applied to a single number: the multiplier at which the round ends.

The crash point is derived from the seed pair by a documented, deterministic function. The curve the player watches is not random; it is a fixed growth function of elapsed time, running until it reaches the number that was already decided.

Separating the two is worth doing carefully in the implementation: one function decides where the round ends, another decides how fast the screen gets there. Only the first one needs to be verifiable.

Between rounds there is a short window in which stakes are accepted and debited. Every accepted bet is a transaction against the wallet with its own id, and the round's participant list is closed when the window shuts.

Late arrivals are refused rather than queued. A bet that lands after the curve has started has to be rejected cleanly, because there is no honest way to include it.

Once running, the server advances the multiplier on a fixed tick and broadcasts it. Clients interpolate between ticks for smoothness, but they never compute the multiplier themselves; the server's value is the only one that settles anything.

Client-side prediction is a rendering convenience. The moment it becomes the source of truth, two players on different connections can see different outcomes for the same round.

A cash-out is a request timestamped against the server's tick, not the client's. If it arrives before the crash point, the win is the stake multiplied by the value at that tick, credited as its own transaction. If it arrives after, the stake is lost and no credit is written.

Auto cash-out is evaluated server-side for the same reason, so a player whose connection drops mid-round still gets the outcome their instruction described.

When the round closes, the server seed is revealed and the round record is written: the hash published earlier, the seed, the client seed, the nonce, the derived crash point and every transaction attached to it.

That record is what makes the round checkable months later. It is also, in practice, what makes support tractable: most disputes are answered by reading it back rather than by taking a position.