What is volatility in casino games?
Volatility (also called variance) describes how widely a game's results swing around its average return. A low-volatility game pays small amounts often; a high-volatility game pays larger amounts rarely. Volatility changes the shape of a session, not the average cost, which is set by the house edge.
Definition
Volatility is a measure of spread. It tells you how far the result of a short series of rounds is likely to sit from the long-run average. Mathematicians call the underlying quantity variance; game descriptions often use the labels low, medium and high.
It is a separate property from the return to player. Two games can share the same percentage and feel nothing alike, because one spreads its payouts over many small wins and the other concentrates them in a few large ones.
Same average, different ride
Bet A pays 2 times the stake with probability 48.5%. Bet B pays 100 times the stake with probability 0.97%. Both return 97% on average, so both cost KES 3 per KES 100 staked.
Over 50 rounds, Bet A wins about 24 times. Bet B does not win at all in roughly 61% of such sessions, because 0.9903 multiplied by itself 50 times is about 0.61.
The player on Bet B will usually lose every stake in the session and will occasionally collect a large payout. The player on Bet A will see a slow, bumpy decline. The average bill is identical.
Why it matters
High volatility makes a fixed balance less predictable: it can vanish quickly, and the rare large win tempts people to keep staking while they wait for it. Low volatility makes losses feel gentle, which can hide how much has been wagered in total.
Neither kind changes the arithmetic described in the guide to how RTP and house edge work. Volatility is a reason to set a firm limit before play, as covered in the guide to session limits.
Questions and answers
Is high volatility better or worse for the player?
Neither in terms of average cost. With the same RTP, the expected loss per shilling staked is identical. High volatility means longer losing runs and a greater chance of emptying a balance quickly, with rare larger wins.
Is volatility shown in the game rules?
Regulation 20(2) of the Conduct of Gambling Operations Regulations, 2026 lists rules of games, odds, house edge and average return to the player as items to display. Volatility is not named in that list, so a game may or may not describe it.