Slots & Gaming Machines
Slot machine jackpot
A slot machine jackpot is the largest payout a slot game can award, either as a fixed sum or a growing progressive prize.
- Maximum prize (UK)
- £10,000 for reel-based machines; linked progressive jackpot up to £20,000 on a premises basis only1
- Maximum charge (UK)
- 50p generally; £100 in casinos where max prize ≤ £500; £2 in other casino cases2
- Example jackpot
- $4,017,954 with winning probability 1/4,382,383, expected return 92¢ per spin on $11.25 bet5
- Must-hit-by hit probability
- 1/(100,000 − j) when current jackpot j ≤ 99,9996
Key points
- Jackpots may be awarded by a specific reel combination, bonus feature, or progressive condition such as a must-hit-by threshold.34
- In progressive systems, the meter grows until a win is triggered or the predefined hit point is reached.36
- On standard slots, each spin is independent and the jackpot outcome is determined by the machine’s random-number process.7
- UK regulations cap the prize at £10,000 for most machines, with linked progressives limited to £20,000 per premises.1
How a slot machine jackpot works
- The machine’s random-number generator determines the outcome of each spin independently.7
- If the spin matches a winning combination or triggers a bonus, the jackpot is awarded.3
- For progressive jackpots, a small portion of each bet adds to the meter until a win occurs.3
- In must-hit-by progressives, a hit point is randomly chosen on a uniform distribution between the start and maximum jackpot.3
Common questions
What are the odds of winning a slot machine jackpot?
Is a change in-slot machine jackpot-thresholds-really-coming?
No regulatory change is currently announced. UK thresholds are set by the Gambling Act 1968 and the Gambling Commission, with a maximum prize of £10,000 and linked progressives up to £20,000.12
How to hit slot machine jackpot?
There is no strategy to influence the outcome. Each spin is independent and determined by a random-number generator.7 Playing maximum bet may be required to qualify for some progressive jackpots, but does not improve the odds.
Where this term is used
Related terms
Sources
- Gaming machine categories gamblingcommission.gov.uk Provides UK regulations on maximum prizes and linked progressive jackpots for reel-based machines.
- The Gaming Act 1968 (Variation of Monetary Limits) Order 2005 legislation.gov.uk Sets the maximum charge for play and prize limits for jackpot gaming machines in the UK.
- Must-Hit-By Progressives wizardofodds.com Explains how must-hit-by progressives work and the uniform distribution of hit points.
- Must-Hit-By Jackpots -- 1/4/2019 - Wizard of Odds wizardofodds.com Describes progressive jackpot conditions and bonus features.
- Shopping Spree Progressive Jackpot at $4 Million - Wizard of Odds wizardofodds.com Gives a real-world example of a progressive jackpot amount, probability, and expected return.
- Slots - Progressive Slots wizardofodds.com Provides the formula for hit probability in must-hit-by progressives as the jackpot increases.
- Slot Machines wizardofodds.com States that each spin on a slot machine is independent and determined by a random-number generator.
Sources are drawn from regulators, universities and published research, and each one is labelled with what it actually is — a preprint is not called a paper. Bookmaker and affiliate pages are never cited here, because a page that sells betting is not a neutral authority on it.