Calculate Your Odds
Enter your number of spins and the drop rate percentage to calculate your probability of success.
Quick Reference: Drop Rates
| Magic | Tier | Drop Rate |
|---|---|---|
| Anti-Magic (Five Leaf) | God | ~0.09% |
| Time Magic | God | ~0.09% |
| World Tree | Mythical | 0.14% (1% rare spin) |
| Light Magic | S | Rare (Update 3) |
| Darkness Magic | S | Rare |
| Fire/Water/Ice/Lightning/Wind | A | Uncommon+ |
| Common Magic | C | 95% (Common Tower) |
Tower Probabilities
Probability Formula
The probability of rolling a specific Grimoire at least once in n spins is:
P(at least 1 success) = 1 - (1 - r)n
Where r is the drop rate and n is the number of spins. This follows a binomial distribution.
Example: With 0.14% drop rate (World Tree) and 1000 spins:
P = 1 - (1 - 0.0014)1000 = 1 - 0.2466 = 75.3%