Feature trigger
A feature trigger is the event on a slot spin that launches a bonus round, most often a set number of scatter symbols landing anywhere on the reels in a single spin. Three scatters is the usual minimum, though some games ask for four, and the paytable of each game states the exact rule. Because the reels are driven by an RNG, a trigger can never be predicted from the spins before it.
How often a feature trigger lands
Trigger frequency is usually quoted as one in so many spins, a long-run average set by the studio’s maths model rather than a schedule. A game with a stated frequency of one in 200 can go 600 spins without a feature, and nothing about that drought makes the next spin more likely to deliver one.
That is the myth worth correcting: a slot is never “due”.
Studios balance how much of the RTP sits in the base game against how much sits in the feature, so higher-volatility games tend to trigger less often and pay more when they do. Where a studio does not publish the figure, it is simply unknown, and a short session of anyone’s play does not supply it.
Kinds of trigger you will meet
The rows below set out the common mechanisms described in game paytables. The details vary from title to title.
| Trigger type | What sets it off | Where it is stated |
|---|---|---|
| Scatter count | Usually 3 or more scatters, anywhere | Paytable |
| Bonus symbols | Set symbols on given reels | Paytable |
| Random trigger | RNG fires the feature on any spin | Game rules |
| Collection meter | Filled meter of collected symbols | Game rules |
| Retrigger | Scatters landing inside the round | Paytable |
| Feature buy | Paid entry, often 50x to 100x stake | Buy menu |
Feature trigger versus feature buy
The term is often confused with a feature buy, where the player pays a multiple of the stake to enter the bonus directly. Buying skips the wait but does not change the outcome, which is still decided by the RNG and can return less than the price paid. Availability of the buy option differs between operators and markets, so its absence on one site says nothing about the game itself.
