What a trigger rate does and does not promise
Studios sometimes publish how often a bonus round triggers on average — one in some number of spins. It is a genuinely useful figure and it is also the figure most often misread, because an average across an enormous sample reads to most people like a schedule. It is not one. A game with a stated rate of one in several hundred spins will routinely go multiples of that without triggering, and that is ordinary behaviour rather than evidence of anything. This page explains what the number describes and the eligibility rule that sometimes sits underneath it.
Averages, droughts and eligibility
Four points below cover what the figure measures, why droughts are normal, and the condition that can stop a feature from triggering at all.
The rate is a long-run average, not an interval
A rate of one in several hundred means that across an enormous number of spins the triggers average out to roughly that density. It does not mean one arrives every that many spins. Each spin is resolved independently, so the count since the last trigger is not an input to anything.
Long droughts are expected, not exceptional
In any independent sequence, gaps considerably longer than the average occur regularly. A drought of two or three times the stated rate is unremarkable. Intuition badly underestimates how common these stretches are, which is where the sense that something is wrong comes from.
Some games gate the feature behind a minimum stake
A number of titles require a minimum bet to be eligible for the feature or for certain prize tiers within it. Playing below that threshold spins normally but can never reach the feature. This detail lives only in the game information panel and is easy to miss entirely.
Buying entry does not change the underlying rate
Where a purchase option exists it bypasses the wait rather than improving anything, and several titles publish a different return figure for the purchased route. The trigger rate for ordinary play is unaffected by whether the option exists.
Frequently asked questions
If a game has not triggered in a long time, is it due?
No. Independence means the spins already played contribute nothing to the next one. This is the same misreading that appears with jackpots and with streak counting in table games; the surface changes but the underlying error does not.
Can I work out the rate myself from playing?
Not to any useful precision. Estimating an event this infrequent needs a sample far beyond what one player accumulates, and small samples produce wildly varying estimates. That is also why the trigger rates circulated in player communities rarely agree with each other.
Why do only some studios publish the rate?
Publication requirements differ by jurisdiction, and beyond return figures much of what a studio discloses is voluntary. Where the rate is absent, the variance rating gives a rough indication of how the value is distributed, which is a related but not identical question.
