Damage calculation help

so damage is reduced by defence and dmamage reduction
Damage is increased by attack (dribble, received pass effect etc)

How does the penetration stat affect damage reduction?
For example, 40% pen against 50% dmg reduction.
Does the defender get 10% dmg reduction (straight up subtraction of pen against dmg reduction) or 30% dmg reduction (40% of 50% subtracted) or is it something else.

 

My bad, just found a seperate thread with basically the same question

 

Damage reduction are multiplicative with all other sources of damage reduction. So the defender's bonus will apply, as well as every other source. Then, you apply penetration to the overall DR value.
Note: Elemental DR is applied as a separate source, so penetration applies to that separately, then, you multiply the Elemental DR source with your regular DR source for overall DR.

In your example, if you have 40% pen against 50% damage reduction and also an additional 15% damage reduction for being a Defender "when being attacked". You multiply all your sources of DR, .5 * .85 = 42.5% damage taken or 57.5% DR.
Then, you apply your 40% pen against that value, .575 * (1 - 0.4/2) = .575 * .8 = 46% DR.