Where the payoff to the player in a game is dependent on chance outcomes, the emv is the average gain the player would achieve per game in the long run. It is calculated as the sum of: each payoff multiplied by the probability of that payoff.

For example:

Showing possible payoffs and chances

The emv is 3 × 0.2+0 × 0.3+(−1) × 0.5 = 0.1 as written in the circle.