To choose a slot, compare three numbers: the return to player (RTP), the hit frequency and the volatility. RTP tells you the long-run cost, hit frequency tells you how often a spin pays anything, and volatility tells you how wide the swings are. Two games can have exactly the same RTP and give you completely different sessions, so the RTP alone does not tell you which one to play.
This guide uses two small machines we built and solved exactly, both returning 87.6%, to show what changes when the RTP stays fixed. One pays often in small amounts and the other rarely in large ones. We then give a checklist for choosing a real game, and the limits of what you can know before you play. The calculations are our own, and the regulatory points come from Nevada and New Jersey rules.
What do RTP, hit frequency and volatility tell you?
Each number answers a different question about a slot.
- RTP (return to player) is the share of money wagered that the game pays back over a very long run. It sets the average cost per dollar.
- Hit frequency is how often a spin pays something, even if the payout is less than the bet. It shapes how lively a session feels.
- Volatility (or variance) is how widely results spread around the average. A high-volatility game has long dry runs and occasional big wins, and a low-volatility game pays small amounts steadily.
Regulators fix a floor on the first number. New Jersey requires a theoretical RTP of at least 83%, and Nevada’s Regulation 14.040 requires at least 75%, according to the Nevada Gaming Control Board. In the New Jersey approval standards we read, there is no requirement to disclose hit frequency, and neither standard publishes volatility as a figure. So the second and third numbers are often something you must infer from the pay table and the top prize.
Two machines with the same RTP
Both machines pay out 87.6 coins for every 100 coins wagered on average. They differ only in how that return is spread.
Steady has 10 stops per reel: 3 cherries, 3 bells and 4 blanks. It pays 10 for three bells, 10 for three cherries, 2 for cherries on reels 1 and 2 only, and 1 for a cherry on reel 1 only.
Volatile has 20 stops per reel: 1 seven, 3 BARs, 4 bells, 4 cherries and 8 blanks. It pays 880 for three sevens, 80 for three BARs, 20 for three bells, 10 for three cherries, 3 for cherries on reels 1 and 2 only, and 1 for a cherry on reel 1 only.
| Steady | Volatile | |
|---|---|---|
| RTP | 87.6% | 87.6% |
| Average loss per 100 coins wagered | 12.4 | 12.4 |
| Spins that pay anything | 32.7% | 21.15% |
| Standard deviation of one spin (coins) | 2.26 | 11.05 |
| Top prize for a 1 coin bet | 10 | 880 |
The standard deviation is the number to look at. Volatile’s is about five times Steady’s, which means its results are about five times as spread out around the same average.
What does the difference look like in real sessions?
We calculated the exact distribution of results for 100 and 500 spins at 1 coin each. Here is what changes.
| After 100 spins (cost 100 coins) | Steady | Volatile |
|---|---|---|
| Ahead | 27.2% | 29.9% |
| Get half your stake back or less | 3.8% | 39.9% |
| Get at least double your stake back | 0% | 4.3% |
| After 500 spins (cost 500 coins) | Steady | Volatile |
|---|---|---|
| Ahead | 11.0% | 20.1% |
| Get at least double your stake back | 0% | 6.1% |
| Get half your stake back or less | 0% | 10.3% |
Three things stand out.
- The volatile machine has the better chance of finishing ahead. At 500 spins, 20.1% against 11.0%. High volatility is the only route to a large result, so players who want a chance at a big session are not irrational to prefer it.
- The volatile machine also has the worse bad outcomes. About 4 in 10 100-spin sessions return half the stake or less, against fewer than 1 in 25 on Steady.
- The average cost is the same. Over very long play, both lose 12.4 coins per 100 wagered. The choice is about the shape of the ride, not the price.
How long will your bankroll last on each?
The average loss per spin is 0.124 coins on both machines, so a bankroll of 100 coins lasts around 806 spins on average. Averages hide the spread. This table shows the chance that a bankroll runs out before a fixed number of spins, betting 1 coin each spin.
| Starting bankroll and session length | Steady runs out | Volatile runs out |
|---|---|---|
| 100 coins, 300 spins | 7.0% | 53.7% |
| 100 coins, 600 spins | 43.1% | 78.5% |
| 50 coins, 300 spins | 52.5% | 81.7% |
The result is a useful rule. A volatile game needs a bigger bankroll, or a smaller bet, for the same session length. A small bankroll on a volatile game often ends early, even though the machine’s average cost is no higher.
Which should you choose?
It depends on what you want from the session, and the maths lets you say so plainly.
- If you want a longer session for your budget, pick lower volatility and a smaller bet. Steady’s 100-coin bankroll got through 300 spins 93% of the time.
- If you want a chance at a large result and can accept a short session, pick higher volatility, and set a firm limit before you start.
- If you want the lowest average cost, pick the higher RTP. Neither volatility changes the cost per dollar wagered.
None of these choices lifts your expected result above a loss. They change how you spend a fixed budget. Our how to win at slots guide goes through this idea in detail.
How do you judge a real game?
You will rarely see RTP, hit frequency and volatility on a real machine, so read what the game does show.
- Find the cost of a spin. Lines times line bet, or the total bet shown. Our how to read a slot pay table guide explains it.
- Look at the top prize relative to the bet. If the top prize is 5,000 times the bet, most of the return sits in rare results, so the game is volatile. If it is 200 times the bet, it is steadier.
- Count how the small wins are built. Many small line wins from common symbols suggest a high hit frequency.
- Check for a published RTP. Some regions and operators publish it, and some games have more than one RTP setting. Treat any published figure as a long-run average.
- Check for extra costs. Bonus buys, side bets and ante options change the cost per spin and sometimes the return.
- Prefer the higher RTP when everything else is equal. A 95% game costs more than a third less per dollar wagered than a 92% game would.
Bonus features add a wrinkle. A game with a big feature often has a lower return from base play, because part of the RTP is reserved for the feature. That is why a game can feel stingy for hundreds of spins and then deliver a large result.
Does a higher hit frequency make a game safer?
Not by itself. Hit frequency counts every spin that pays anything, including spins that pay less than the bet. On Steady, 32.7% of spins pay, but the most common payout is 1 coin, which only returns the stake of that spin. So a large share of those hits are what the industry sometimes calls losses disguised as wins: the machine celebrates while your balance falls.
What matters for how safe a game feels is the combination of hit frequency and the size of the prizes behind it. A game that hits often and pays small amounts has a narrow spread, like Steady, with a standard deviation of 2.26 coins per spin. A game that hits rarely and pays large amounts has a wide spread, like Volatile, at 11.05. Neither is safer in terms of cost, and only one of them is safer for a small bankroll.
Does the choice of game change your odds on each spin?
No game gives better odds than its design allows, and no spin is influenced by earlier spins. The choice is made once, before you play. After that, each spin is independent. The earlier steps help you decide how much to spend and how long to stay.
What mistakes do players make when choosing?
- Choosing by theme or sound. Neither says anything about the maths.
- Choosing the biggest jackpot. The bigger the top prize, the more of the return sits in a rare event.
- Assuming a high hit frequency means a good game. Many of those hits pay less than the bet.
- Switching machines to find a “better” one. Moving from machine to machine does not change the maths of any spin.
- Raising the bet to chase a loss. A bigger bet only makes the average loss larger.
Decide the session budget first, then choose the game and bet that fit it. Our guide to setting a gambling budget and time limit shows how, and the Safer play toolkit lists tools and support. If gambling is causing harm, visit our get help page.
Slot machines are legal in some places and not in others. See is gambling legal where you live before you play.
Where should you go next?
For the basics, read how slot machines work. To test common beliefs, read slot machine myths. To plan the money side of a session, read a slot session and bankroll plan.