What is Feature Trigger?

A feature trigger is the specific symbol combination a slot requires to launch a bonus round or free spins feature, most commonly landing a set number of scatter symbols on the reels in a single spin. It is the gateway between base-game play and the higher-paying feature that usually carries a slot's biggest win potential, which is why the trigger rules and their frequency are among the most important numbers in any slot's paytable. The exact requirement varies by game. A typical trigger needs three or more scatters anywhere on the reels, but some slots demand specific reel positions, symbol collection over multiple spins, or landing a dedicated bonus symbol. The number of scatters landed can also scale the reward: three might award 10 free spins, four might award 15, and five might award 20 plus a cash multiplier. Worked example: on a 5-reel slot, the trigger needs three or more scatters to award free spins. If each of the five reels shows a scatter with probability 1/20, the chance of landing exactly three scatters is roughly 0.98% per spin, meaning the feature triggers on average about once every 100 spins. At £0.50 per spin, that averages one feature roughly every £50 staked, though variance means real results swing widely around that figure. For players comparing slots, trigger frequency and the average feature payout together largely define a game's rhythm and volatility more than the headline RTP alone. A rare, generous trigger signals high volatility; a frequent, modest one signals low volatility. Compare with scatter, free spins, retrigger and bonus buy.