First of all this guide does not include attack vs defence calculations. Here we assume that a hit is acheived and we only evaluate the effect of damage and protection when the hit is already acheived.

Damage is given by DRN + advantage - another DRN.

Vertical value is average damage. Horizontal axis is advantage values.

Advantage is how much a base damage value greater or smaller than a protection value.
Damage obviously cant be negative.

Results on the graph are averaged over a large amount of tests. I have displayed a linear proportional y=x graph for comparison (in red).


Yellow graph is for when you are attacking a humanoid 10hp target. (you cant deal 30 hp to a 10 hp unit so the damage is capping at 10.

The last graph gives average hits to kill target. Two lines are given: for 10hp human and 32 hp giant.