Mitigation Lab
Armor, MR, lethality and penetration — step by step, with the formula and the curve in plain sight.
Reduction = R / (100 + R). Penetration slides you down the curve: the same hit lands harder.
About this mode
This tool makes LoL's defensive math transparent. You set the target's resistance (armor or MR) and your penetration sources —flat reduction, % reduction, % penetration and lethality— and it shows, step by step and in Riot's real ORDER, the effective resistance, the damage multiplier, how much damage you reduce and the effective HP (EHP).
Order matters: flat reduction first, then % reduction, then % penetration, and finally flat penetration or lethality (which never drops resistance below 0). The curve on the right shows how your penetration slides you down the reduction curve: the same hit lands harder.
FAQ
Why is lethality weaker against tanks?
Flat penetration subtracts a fixed amount of armor; against high resistances that subtraction barely moves the multiplier. Percent penetration scales much better into tanks.
How much flat penetration does my lethality give?
Lethality × (0.6 + 0.4·level/18). At level 18 it is 1:1; at level 1, around 62%. The tool does the conversion for you.
Can penetration make resistance negative?
Flat penetration never goes below 0. Only armor-reduction effects (not penetration) can take resistance negative and amplify the damage taken.