Almost every online slot review leads with a number like 96.5%. That is the RTP, or return to player. It is useful, but only if you know what it is measuring.
What RTP is
RTP is the share of all money wagered on a game that the game is designed to pay back to players over its lifetime. A slot with a 96% RTP is built to return $96 of every $100 wagered, across all players and a very large number of spins. The other $4 is the house edge.
The key words are "over its lifetime". RTP is a statement about millions of spins. It is not a prediction about yours.
What it does not tell you
It does not tell you what happens in a session. In a few hundred spins, results swing far above and below the long-run figure, and the swings are larger on high volatility games. You can lose a full budget on a 97% game and walk away ahead on a 92% one. Over enough play, though, the lower number costs you more.
It also does not mean a machine is "due". Each spin is independent. A slot that has not paid for an hour is no more likely to pay on the next spin than one that just hit.
The same slot can have several RTPs
This surprises people. Many online slots are released in more than one RTP version and the casino chooses which one to offer. Gates of Olympus, for example, has a default 96.50% version, and its maker also supplies 95.51% and 94.50% versions. The game looks identical. The only way to know which you are playing is to open the info or help screen in the game at that casino.
The RTP figures in our Top 100 are the maker's default version.
Why casino floor machines do not show one
Land-based machines work the same way, with more versions. A maker ships each title with a range of payback settings, and the casino picks one for each machine, within limits set by its gaming regulator. Regulators set a legal floor. In Nevada, for example, the minimum is 75%, although machines there return far more than that on average. The same title can be set differently at two casinos, and at different denominations in the same building.
That is why our list shows "Set by casino" for floor machines. Anyone quoting a single RTP for a casino floor slot is guessing.
How to use RTP sensibly
- Treat it as a long-run cost, not a forecast. A lower RTP means each dollar wagered costs you more on average.
- Compare like with like. RTP matters most when choosing between similar games.
- Check the version. For online play, look at the game's info screen before you start.
- Pair it with volatility. RTP tells you the average, volatility tells you how wild the ride is.
And remember that no RTP below 100% makes a slot a way to earn money. It is the price of the entertainment.