What is Bonus Frequency?

Bonus frequency is how often a slot triggers its main bonus round on average, typically expressed as roughly one occurrence in a given number of spins. A slot advertised with a bonus frequency of 1 in 250, for instance, lands its feature about once every 250 spins across a very large sample, so on average roughly 0.4% of spins produce the bonus. It is a long-run average driven by the random number generator, not a countdown, so the feature can arrive on consecutive spins or stay absent for far longer than the headline number. Bonus frequency is distinct from hit frequency, which counts any winning spin including tiny line wins. It usually correlates with volatility: low-volatility slots tend to trigger bonuses more often for smaller rewards, while high-volatility titles trigger them rarely but pay bigger when they do. Worked example: on a slot with a stated bonus frequency of 1 in 200 spins, a player spinning at £0.50 per spin would expect to stake around £100 (200 x £0.50) between bonus triggers on average. Over a 500-spin session they might expect roughly two or three bonus rounds, though variance means the real count could easily be zero or five. For players and affiliates, treat bonus frequency as an average, never a guarantee, and read it alongside RTP and volatility rather than in isolation. A rare, high-paying bonus is not inherently better than a frequent, modest one. Compare with hit frequency, slot volatility, RTP and the feature trigger that starts the bonus round.