Free spins slots explained: triggers, retriggers, and feature rules.

Free spins are additional game rounds awarded under the slot's feature rules. They are not a separate win system: the slot can keep its paylines, pays-anywhere, Megaways, or another underlying rule while changing symbols, multipliers, reel state, or available features for a set number of rounds.

UK Gambling Commission technical standards say applicable rules and bonus-round behaviour should be available and understandable before play. Check the in-game help for the exact trigger, initial award, retrigger, and version because similar feature names do not make two slots behave alike.

A trigger can use scatters anywhere on the grid or bonus symbols on named reels. Book of Dead awards 10 spins from three book symbols, while Great Rhino needs three bonus symbols on reels two, three, and four for its 10-spin feature.

Starting totals also vary. Dead or Alive 2 begins with 12 spins and a choice of three modes; Wild West Gold starts with eight; Buffalo King Megaways awards 12 to 22 spins from four to six bonus symbols. The symbol count and allowed positions are part of the rule, not decorative detail.

Book of Dead selects one ordinary paying symbol to expand during free spins. Dead or Alive 2 instead lets the selected mode change wild behaviour through a fixed win multiplier, multiplier wilds, or a progress meter. The same starting-spin label therefore leads to different feature states.

Wild West Gold keeps 2x, 3x, and 5x multiplier wilds sticky during the feature. Great Rhino turns every rhino symbol wild in its free spins, while its sticky-rhino Super Respins remain a separate feature. Compare the exact symbol change rather than treating every wild-led round as equivalent.

Sweet Bonanza adds the values of multiplier symbols at the end of a winning tumble sequence. Gates of Olympus uses a feature-wide total multiplier that grows when multiplier symbols land. One asks you to read the current tumble; the other asks you to track state across the round.

Retriggers can also change the useful life of a feature. Three or more bonus symbols add five spins in Buffalo King Megaways, while two to five scatters add four to 20 spins in Wild West Gold. A retrigger rule matters only when the required symbols and positions are stated clearly.

The feature is one part of a slot's mathematics. Its presence does not prove a higher RTP, lower volatility, larger maximum win, or more frequent payouts. Those values must come from the exact reviewed version and remain separate comparisons.

A feature can also concentrate much of a high-volatility game's value without showing how often it starts. Read the review's RTP, provider volatility label, maximum, and feature route together; none can be calculated from the words free spins alone.

Promotions sometimes reuse the phrase free spins, but they are not the in-game mechanic covered here. This guide deals only with extra rounds written into a slot's own rules and the feature changes that happen during those rounds.

Keep promotional eligibility and terms separate from the trigger, retrigger, symbol, and multiplier rules inside a reviewed game.