Estimate the long-run reward value of a randomized drop used in game development. Enter three possible reward values and their independent outcome probabilities, then compare the expected value per attempt with the attempt cost. The result is useful for economy tuning, reward-table reviews, and transparent scenario checks. It does not predict a particular opening; it summarizes the probability-weighted average across many identical attempts.
EV per attempt = (Value A × Probability A) + (Value B × Probability B) + (Value C × Probability C)
Probabilities are converted from percentages to decimals. Expected net value equals planned attempts × (EV per attempt − cost per attempt).
The main result is the average reward value per identical attempt over a large number of trials. The attempt total scales that average; it is not a guaranteed payout.
Random outcomes are volatile. Use this estimate for design and comparison, not as a promise of what any player will receive.
With rewards of 100 at 5%, 25 at 20%, and 5 at 50%, expected value is 100 × 0.05 + 25 × 0.20 + 5 × 0.50 = 12.50 per attempt. At a cost of 10 for 20 attempts, expected total reward value is 250 and expected net value is 50.
Yes. Enter the no-drop outcome as a zero-value result or make sure all listed outcome probabilities sum to no more than 100%.
Yes. The value-to-cost ratio compares the calculated expected reward value with the cost per attempt.
Expected value is a long-run average. A small number of attempts can be far above or below it because drops are random.
They may total less than 100% when the remaining chance represents no reward. They must not exceed 100%.
Yes. Use any consistent value unit for rewards and cost; the ratio remains valid when all entries use the same unit.
| Variable | Meaning |
|---|---|
| Reward value | Comparable economic or utility value |
| Probability | Chance of that outcome per attempt |
| Expected value | Probability-weighted average reward |
| Expected net | Expected reward minus total attempt cost |