Cookies on the Gambling Commission website

The Gambling Commission website uses cookies to make the site work better for you. Some of these cookies are essential to how the site functions and others are optional. Optional cookies help us remember your settings, measure your use of the site and personalise how we communicate with you. Any data collected is anonymised and we do not set optional cookies unless you consent.

Set cookie preferences

You've accepted all cookies. You can change your cookie settings at any time.

Skip to main content

Key terms relating to live return to player performance monitoring of games of chance

Theoretical RTP

This is the designed return to player percentage of the game, it will also be the advertised RTP of the game as displayed in the player facing rules, as per RTS 3C.

Actual RTP

Calculated using the generated win and turnover figures of the live (operational) game. It shows the RTP the game has actually achieved for the past period as covered by the selected win and turnover amounts.


Most commonly the standard deviation of the game is used to represent the game’s volatility. A highly volatile game will have a larger tolerance and might be comprised of prizes falling into the ‘very large but rare’ category. A low volatility game will be much more predictable and mostly comprised of prizes falling into the ‘small and often’ category. Standard deviation is a mathematically calculated figure (square root of the game’s variance, where the variance depends on the game’s cycle and prize frequency).


The total of all stakes made on the game, this will include reinvested winnings awarded during play.


The total of all prizes awarded during game play. The GGY of a game will be the turnover minus win.

Previous page
Measuring progressive jackpots
Is this page useful?
Back to top