About and methods

RTP Guide is a free, independent reference for slots built on Engine (formerly Stake Engine). Every Engine game publishes its full math, and we turn it into numbers a player can use: the RTP of every mode, how rare the max win is, how often a round pays back its cost, and what a bonus buy costs over time.

We are not affiliated with, endorsed by or operated by Stake or Engine. This site carries no casino links and no offers.

Where the numbers come from

• Game math: the Engine fairness API (fair.engine.io). It lists every game, every math version and every mode, and publishes each mode's full outcome table.
• Popularity, release dates and platform totals: Engine Insights. Turnover and player counts cover the last 30 days and are in US dollars.

Data is refreshed daily. Each page shows the figures for the game's active math version.

How we calculate

• Cost of a mode is a multiple of the base bet. Base spins cost 1×. Modes costing more than 1× and less than 20× are called boosted spins; 20× or more is a bonus buy.
• RTP is the mode's reported return. When we have downloaded a mode's full table we recompute it as the sum of payout × weight, divided by total weight and by the mode's cost, and check it against the reported figure.
• Max win is the largest payout in any mode, as a multiple of the base bet. Max win odds are "1 in N rounds" of that mode.
• Pays anything, pays nothing and returns the cost are the rates at which a round pays more than zero, exactly zero, or at least what it cost.
• Expected cost per round is cost × (1 − RTP), in base bets: the average loss per round over the long run.
• Volatility uses the game's base-mode standard deviation. We split all games into thirds: the lowest third is Low, the middle third Medium, the top third High.
• RTP cut is flagged when the active version's base RTP is at least 0.5 points lower than the best earlier published version.
• Similar games are matched on volatility, max win, RTP and whether the game has a bonus buy, never on theme.
• Mini games (dice, pick-a-side and similar, with more than 12 modes) are kept out of slot lists by default.

Some figures from the fairness API's summary endpoint are not formally documented; we matched them against full-table calculations before using them. If you spot a number that looks wrong, please tell us.

What these numbers can't tell you

RTP and odds describe the very long run. A single session can end far above or below the average, and every mode returns less than it costs over time. Nothing on this site predicts results or suggests a way to change them.