For those who care about these kind of things:
Damage Taken = Floor( 2^(-Damage Resistance/50) - 1 )
e.g.
Damage Resistance = 50 => Damage Taken = 2^(-1) - 1 = -0.5 => -50%
Damage Resistance = -25 => Damage Taken = 2^(0.5)-1 = Sqrt(2)-1 = 0.416 => +41%
Due to the exponential, this becomes very large very quickly for low values (not sure how low Ramage Resistance can go, but already -50 doubles damage taken (Damage Reduction = +100%), if it is -100, Damage taken =+300%. And obviously asymptotes to -100% as Damage Resistance goes to infinity (so diminishing returns).
Damage Taken = Floor( 2^(-Damage Resistance/50) - 1 )
e.g.
Damage Resistance = 50 => Damage Taken = 2^(-1) - 1 = -0.5 => -50%
Damage Resistance = -25 => Damage Taken = 2^(0.5)-1 = Sqrt(2)-1 = 0.416 => +41%
Due to the exponential, this becomes very large very quickly for low values (not sure how low Ramage Resistance can go, but already -50 doubles damage taken (Damage Reduction = +100%), if it is -100, Damage taken =+300%. And obviously asymptotes to -100% as Damage Resistance goes to infinity (so diminishing returns).