valadil

2008-11-29, 03:06 AM

Tonight at game we had the chance to pick armor that was +1 AC or +1 DR. Supposedly our resident power gamer who wasn't there that night had determined that 1 point of AC mitigates just as much damage as 1 point of DR. He wasn't there to ask though, so I'm wondering if anyone here can show me the math.

I'm too sleepy for any definitive conclusions, but I feel like they'll give you different values depending on the kind of damage being dealt. For what it's worth, I'm considering a range of 20 attacks, where the d20 ranges from 1 to 20. I am not taking botches or natural twenties into consideration - for now it's just head math and my head is a very sleepy place right now. Also, this is 4th edition, if it matters.

If you take 10 per hit and get hit on a d20 roll of 10, you expect to take 100 damage over 20 dice. Increasing DR or AC will mitigate 10 damage.

So what if we get hit on a 10 and take 20 damage per hit? Increasing AC drops one hit, so you're looking at 180 over 20 attacks, but DR would leave you taking

But what if we're getting hit on a 10, taking 1 damage per hit? The +1 AC guy takes 9, but the +1 DR guy takes nothing.

Also keep in mind that as the target number for the d20 goes up, DR will protect against less and less. If you need a 19 or 20 to hit, DR will only affect 10% of your rolls.

Conversely, if you need a 2 or higher to hit, DR affects rolls that aren't 1s.

Does this even matter or does it just balance out in the end?

I'm too sleepy for any definitive conclusions, but I feel like they'll give you different values depending on the kind of damage being dealt. For what it's worth, I'm considering a range of 20 attacks, where the d20 ranges from 1 to 20. I am not taking botches or natural twenties into consideration - for now it's just head math and my head is a very sleepy place right now. Also, this is 4th edition, if it matters.

If you take 10 per hit and get hit on a d20 roll of 10, you expect to take 100 damage over 20 dice. Increasing DR or AC will mitigate 10 damage.

So what if we get hit on a 10 and take 20 damage per hit? Increasing AC drops one hit, so you're looking at 180 over 20 attacks, but DR would leave you taking

But what if we're getting hit on a 10, taking 1 damage per hit? The +1 AC guy takes 9, but the +1 DR guy takes nothing.

Also keep in mind that as the target number for the d20 goes up, DR will protect against less and less. If you need a 19 or 20 to hit, DR will only affect 10% of your rolls.

Conversely, if you need a 2 or higher to hit, DR affects rolls that aren't 1s.

Does this even matter or does it just balance out in the end?