Quality reroll probability and cost calculator

Search for a supported T4 to T8 item and select its current quality. AU uses the item’s tier, enchantment, material count and artifact category to calculate the charge. Starting quality affects both the charge and the available quality transitions.

Expected attempts and cost describe repeated random outcomes under the model. When the quality changes before the target is reached, the next attempt can have a different cost and probability. Multiplying the first attempt’s price by a fixed number of attempts does not reproduce the full multi-quality calculation.

To isolate the uncertainty, suppose a hypothetical repeated attempt has a constant 1% chance of success and costs 1,000 silver, with failures leaving the state unchanged. Expected attempts are 1 ÷ 0.01 = 100 and expected cost is 100,000. But the chance of still failing after 100 attempts is 0.99 to the power 100, approximately 36.6%.

That example is not AU’s probability table for a particular item. It shows why reaching the expected cost does not guarantee the target. A long run of failures does not make the next independent attempt more likely to succeed.

Compare the incremental cost of buying the target quality with the expected reroll cost, then consider how much uncertainty you can afford. Include the value of the item you already own when comparing complete acquisition routes.

Set a spending limit before starting. A low average cost can still have an expensive tail, and the calculator cannot predict your actual result. The model is useful for understanding probabilities and comparing costs, not for promising a successful upgrade within a budget.