Expected Spins
Expected spins are calculated as 1 / perSpinRate. This is an average over many repeated sessions,
not a promise that a player will hit by that number.
Transparent math
Methodology
The calculator uses a simple independent-spin model. It is useful for planning and sanity checks, but it is not a promise and does not prove how the game server handles every roll.
Core Formula
Chance to hit at least once after n spins:
1 - (1 - perSpinRate) ^ n Chance to miss every spin:
(1 - perSpinRate) ^ n Confidence Thresholds
To find spins needed for 50%, 75%, 90%, or 95% confidence, the planner solves:
ceil(log(1 - confidence) / log(1 - perSpinRate)) Specific Family Rates
When targeting one family, the current model divides the rarity pool equally across families in that rarity. That is marked as estimated because exact per-family weights are not independently verified.
2x Rate Mode
2x mode doubles the Legendary and Mythical rarity pools and reduces Common by the same total amount. Other rarity pools stay unchanged in the current model.
What Is Not Modeled
The headline odds do not include pity, prestige rate bonuses, storage decisions, trades, hidden server-side mechanics, or any changed rates after a game update. If the game publishes clearer official rate behavior, this page should be updated before the calculator copy changes.
Data Sources
Data version: aotr-family-rates-2026-05-17. Last updated: 2026-05-17.