How to use this calculator
- Assign a consistent value to the target reward.
- Enter the published or modeled drop chance.
- Add the number and cost of attempts.
- Compare expected reward value with total cost.
Estimate the average value produced by a randomized reward in a guild program. Enter the item value, drop chance, attempts, and cost per attempt to see expected value per attempt, expected total value, and net expectation. This is a probability-weighted planning estimate—not a promise about any individual player's outcome.
For the guild community, expected value is a long-run average across many comparable attempts. A positive net expectation does not mean every participant will profit or receive the reward.
Attempts are treated as independent and the reward value and probability are assumed constant.
With a $50 reward, 5% drop chance, 20 attempts, and $1 cost per attempt, expected value is $2.50 per attempt. Expected total reward value is $50, total cost is $20, and net expected value is $30.
No. Twenty attempts produce one expected drop on average, but an individual run can yield none or several.
Use a consistent personal utility or replacement-cost estimate and label it as subjective.
No. The basic model assumes a constant independent chance; changing odds require a separate probability model.
Yes. A rare high-value reward can lift the average even when many individual outcomes are below cost.
Only if duplicates retain that value. Otherwise enter the duplicate's salvage, resale, or utility value.
| Variable | Meaning |
|---|---|
| Reward value | Value received when the target drops |
| Drop chance | Independent probability per attempt |
| Attempts | Number of trials in the scenario |
| Attempt cost | Cost paid for each trial |