The value for “Luck” perk in hero statistics panel is given as the sum of all luck perks used, or ∑pi where pi are the individual luck perks.
However, in this great post developer Lisa described the maths and how luck perk works:
It is also describes how the effects of multiple individual luck perks are combined: When you have multiple luck perks pi, together they have the same effect as a single luck perk with the value p=1-∏(1-pi).
Please fix the value in the hero statistics panel to match the correct combined luck perk value. The sum that is now shown is useless and misleading. For example, when you have 2 luck perks with 10%, the panel now shows 20%. The correct value is 1-(1-0.1)*(1-0.1) = 0.19 = 19% .