Each time you attack, the Bun-Bit makes a save. The save is CHA/LUK vs. CHA/LUK with a -20 penalty for the monster (so it favors you). The actual damage reduction is calculated using this formula: (1 / (1 + [monster CHA] / 200) - 0.3) / 0.7 Your damage will be multiplied by the number you get from the formula above.