Certifiable model: crash = RTP ÷ (1−u), with (1−RTP) chance of an instant bust. This gives a fixed house edge at any cash-out target. Payouts are capped by Max win × and Max payout for liability control.

Before each round the server publishes SHA-256(serverSeed). After the round the serverSeed is revealed, so anyone can recompute HMAC-SHA256(serverSeed, clientSeed:nonce) → the crash point. Try changing the nonce to see a different round.

When you hit your loss limit, betting pauses. Reality checks remind you how long you've played. In production these bind to the player account and the jurisdiction's rules (e.g. Georgian RG requirements).