Free Spins
A feature that grants a set number of slot spins the player does not pay a stake for, while any winnings are still added to their balance.
Definition
Free spins are a bonus round in which a player is granted a fixed number of slot spins without a stake being deducted from their balance, while any resulting wins are still paid. In a game's math model they are typically triggered by a symbol combination (such as scatters), played at the bet level that triggered them, and often carry enhancements like win multipliers, extra wilds, or the chance to retrigger. Because the feature can account for a large share of a game's theoretical return, designers deliberately allocate part of the total RTP to it and use it to shape volatility. The term also describes an operator promotion — a set of pre-funded spins on a chosen game — which is a separate mechanic usually governed by wagering requirements and other terms.
Worked example
A video slot advertises a 96.5% RTP, of which the studio's math allocates roughly 30% to its free spins feature. A player betting £1 per spin lands three scatter symbols, triggering 10 free spins that play at the same £1 level with a 3x multiplier applied to every win — no further stake is taken for those 10 spins. If the round returns £22 in total wins, that amount is credited to the balance even though no additional £10 was wagered. Landing three more scatters during the feature would retrigger it, adding another 10 spins.
Why it matters
Free spins are one of the most recognisable slot features and a core lever in game design: they concentrate excitement, carry a meaningful share of a title's RTP, and are a primary tool for tuning volatility. Professionally, the term sits at the intersection of three disciplines — math (how much return and variance the feature holds), promotions (free-spin offers used to acquire and retain players), and compliance (how such offers and any 'free' claims must be presented). Confusing the in-game feature with a promotional free-spin bonus leads to errors in both RTP analysis and terms-and-conditions review.
Related
Note: The in-game feature definition is stable across slot studios. The promotional variant varies widely by operator and jurisdiction — stake value per spin, wagering requirements, maximum winnings, expiry, and eligible games are all set locally, and advertising rules differ (e.g. UK CAP/ASA standards on transparent significant terms, and the growth of 'wagering-free' spins in some regulated markets). Whether free-spin winnings pay as withdrawable cash or restricted bonus funds also depends on the operator.