Three levels instead of one
A single large jackpot hits rarely and pleases almost no one. A three-tier system solves this: mini (cap 500) drops frequently and maintains engagement, major (5000) is a mid-tier prize, grand (50000) is a rare big event.
Each level is a separate pool with its own counter and drop probability. Winning one level does not reset the others.
Where does the pool come from
The pool is topped up by a 2% contribution from each bet — but this is "casino accounting," not a deduction from the player: your winnings and balance are not reduced by this contribution. The jackpot prize is not included in the game's RTP and does not count toward the leaderboard — it's on top.
The chance to hit the jackpot grows as the pool increases: the more accumulated, the higher the drop probability, and at the cap, a guarantee kicks in — the pool cannot grow indefinitely.
Why a double payout is impossible
When two players "clear" the same level almost simultaneously, it's crucial that only one receives the prize. Jackpot claim is an atomic database operation: the first request takes the pool, the second gets a denial. Dual payout is technically impossible.
This is the same fairness logic as in provably-fair: the outcome does not depend on implementation luck, it is protected at the data level.