What are the odds of Lightning Storm on a single Lightning Storm round?

2.58% per round, or about 1 in 39. Every round is independent, so this number never changes with what came before.

How many Lightning Storm rounds until Lightning Storm is likely?

On average one hit every 39 rounds; half of all waits are over within 27 rounds. For a 90% chance of at least one hit you need 89 rounds, for 99% about 177.

Is Lightning Storm "due" a Lightning Storm after a long wait?

No. A wait of 120 rounds without Lightning Storm happens 4.4% of the time from any starting point, and the next round still has the same 2.58% chance. The calculator tells you how unusual a wait is, not that a hit is coming.

Lightning Storm Bonus probability calculator

Lightning Storm lands on 2.58% of Lightning Storm rounds (1 in 39). Pick an outcome and a number of rounds to see the odds, the average wait and how unusual the current drought is.

Game

OutcomeNext N roundsRounds since last hit

At least once in 50

99.9%

Chance per round

12.96%

1 in 7.7

Average wait

median 5 rounds

Rounds for 90% / 99%

17 / 34

A wait of 0 rounds without Monster Mash has a 100.0% chance of happening from any starting point: common - waits this long happen all the time. The next round's chance is still 12.96%.

Formulas: P(at least one in N) = 1 - (1 - p)^N; average wait = 1 / p; P(wait ≥ k) = (1 - p)^k.

Theoretical p = the published rules; source: content-src/guides/lightning-storm/rtp.md (39-segment Digi Wheel, published Leaf/Number RTP; bonus-round shares are our 90-day observed split, re-randomised every spin).

Each round is independent: past results do not change the next round's odds, and no wait makes an outcome "due". Theoretical figures come from the provider's published rules; observed figures come from our own tracker and change as rounds arrive. 18+. Past results do not predict future outcomes. Play with money you can afford to lose.

Frequently asked questions

What are the odds of Lightning Storm on a single Lightning Storm round?: 2.58% per round, or about 1 in 39. Every round is independent, so this number never changes with what came before.
How many Lightning Storm rounds until Lightning Storm is likely?: On average one hit every 39 rounds; half of all waits are over within 27 rounds. For a 90% chance of at least one hit you need 89 rounds, for 99% about 177.
Is Lightning Storm "due" a Lightning Storm after a long wait?: No. A wait of 120 rounds without Lightning Storm happens 4.4% of the time from any starting point, and the next round still has the same 2.58% chance. The calculator tells you how unusual a wait is, not that a hit is coming.
Where do the theoretical and observed numbers come from?: Theoretical odds use the published rules (content-src/guides/lightning-storm/rtp.md (39-segment Digi Wheel, published Leaf/Number RTP; bonus-round shares are our 90-day observed split, re-randomised every spin)). Observed figures come from the rounds our tracker has recorded and change as new rounds arrive.

More on Lightning Storm: live results · RTP & odds · bonus rounds · Bet value calculator