Progressive Jackpot
A shared prize that grows a little with every bet placed on a game (or network of games) until one player wins it, at which point it resets to a starting amount.
Definition
A progressive jackpot is funded by diverting a small, fixed percentage of each qualifying wager into a communal pool that keeps climbing until it is triggered and paid out, after which it drops back to a pre-set seed (reset) value. Jackpots can be standalone (one game), local (linked machines or games at a single operator), or wide-area (pooled across many operators), and are frequently split into tiers such as Mini, Minor, Major and Grand. The jackpot contribution forms part of the game's overall theoretical Return to Player (RTP), but because a win is rare and very large, the return most players actually experience is lower and highly volatile. The prize may be awarded through a bonus feature, a specific symbol combination, or a random "mystery" or "must-drop" mechanic.
Worked example
Consider a networked slot advertised at 96% RTP that routes 1% of every bet into a Grand jackpot seeded at £10,000. On a £1 spin, £0.01 feeds the pool and, on average, about £0.95 is returned through ordinary wins (1% + 95% = the 96% RTP). If 4,000,000 qualifying spins are placed across the network before the jackpot lands, the meter reads £10,000 + (£0.01 × 4,000,000) = £50,000; the player who triggers it wins that full amount and the meter resets to £10,000 to climb again. Real-world wide-area progressives such as Microgaming's Mega Moolah have paid single wins in the tens of millions of euros, but the probability of any individual spin hitting is extremely small.
Why it matters
For players, the headline figure is a marketing draw, not an expectation: the contribution that funds it slightly lowers the base-game return, and the chance of winning is minuscule, so a jackpot must never be framed as realistic income or "easy money" (UK CAP 16.3.4). For operators and studios, jackpot design is a balance of engagement, RTP allocation, liability funding (who covers the seed and the eventual payout), and regulatory limits on pooling across operators. Grasping contribution rates, seeding and tiering is essential to modelling game economics, marketing compliantly, and reconciling jackpot liabilities on the balance sheet.
Related
Note: Core mechanic is a stable definition. Specifics vary by operator, game supplier and jurisdiction: contribution rates, seed values, tier structures, and whether a jackpot is standalone, local or wide-area are all configurable, and some regulators restrict or prohibit cross-operator (wide-area) pooling. How the seed and payout are funded (operator vs. reserve/insurance) and the tax treatment of wins also differ by market. Cited record wins are approximate and historical — verify current figures and supplier configuration before publishing.