Alright i'm pulling these ideas straight from the WH40k RPG books, 3 of them
First, Scattering: If something (generally bouncy and explosive) misses the intended target, you roll on a scatter chart to see which direction it goes. The scatter chart looks like this:
(Perspective of being directly above the object in question) d10: 1:Northeast 2:North 3:Northwest 4:West 5:East 6-7:Southwest 8:South 9-0:Southeast
The north/south/east/west aren't literal directions, but rather directions from the perspective. It also works for enemies who are either on fire or covered in acid
Second: Willpower tests for enemies in immense pain (i.e. on fire, covered in acid, etc.) The HC code would be GM dependant, i like to be a bit brutal if you're on fire but that's for the GM to decide but one thing is if the character fails, all s/he does for the round is flail around screaming, probably in a random direction determined by the scatter chart.
Third: Hit location, i loved the way only war did it, what you did is you took your attack roll and reverse it, then compare to the chart, say you rolled a 54, and it hits! What you do is reverse it, so you then have 45, then you compare it to the chart
Head:1-10 R. Arm:11-20 L. Arm:21-30 Torso:31-70 R. Leg: 71-85 L. Leg: 86-100