Randomized Damage Reduction (DR)

Have you considered using 1d6+# mechanics? For example, if you want to defend against 2d6, have the defender use 1d6+2 or 2d4. It'll ensure that you don't get totally demolished by a 1 defending a 12, depending on how you want it balanced.

three things...

one, I accidentally switched the attacker and defender's rolls in my example. Sorry :-[

two, this was totally me just brainstorming an idea but I have since been thinking along the lines of what RaynRay is suggesting with the custom dice.

three, below is an explanation of my thinking if you are still interested in understanding the original idea:

Looking over your original post "Damage tables or just d6 variations? for dark fantasy game..." I see where more of the confusion is coming from.

You are actually just using the 2d6 rolls to correlate to physical, magical or elemental attack on a table.

I missed this and so wrongly assumed that the attack roll was the physical attack with any magical or elemental bonuses added to that. In my example the rolls were the physical attack countered by the armor rolls. The magical and elemental attack points were a fixed # that would be negated if that armor had an inherent defense against that type.

To clear up how I calculated things...

Attacker rolls: 4, 3

Defender rolls: 6, 2, 4, 2

The 4 physical is blocked by the armor while the 3 physical passes through the armor. The Darkness damage of 3 is blocked because the armor defends against darkness. The Magical damage of 3 goes through the armor. Outcome: Physical damage 3, Magical damage 3, total is 6.

Hopefully things are less confusing now. Like I said, I was just kicking around an idea.

Formula D is a racing game where you use modified dice to determine your car's speed depending on what gear you're in. For example, the Green die only shows numbers 7-12, and the red die only shows 4-8.

The game itself isn't my favorite, but the dice they use are a great idea.

Here's a review of the game. It doesn't show the dice a whole lot, but will give you the gist of how they work:

http://www.youtube.com/watch?v=hSpyKrxT9aw

"So with the system you are describing, just to clarify, do you roll 2d6 for your damage total and then apply the armor against the roll?
So say I roll 2d6 for damage total against heavy armour and I roll a 3 and a 6. The heavy would cancel the 6 and the 3 would get through , thus giving the person 3 total damage?"

Yep, you've got it. You can add in more dice if you want, I haven't worked out the math, but it should maintain the same sort of proportions across the different armour ratings, just up the values across the board. I think it's interesting to compare the different armours with the same averages, 4-5 and 2-4 both average 4 damage, however 2-4 gives a 25% chance of a zero compared to 4-5 giving 11% chance of zero.

"Generally speaking though , is +x to total result more or is it less powerful than +x bonus dice? That's what I'm wondering too..."

It depends really, each extra dice is effectively the same as adding 3.5 on average over an infinite number of rolls... however, for any specific roll you have the full range of possibilities. It depends what you mean by powerful, and what value x takes. If x is 9, I'll take it over an extra dice any day, but if it's 4, then I'd be less sure..

Another thing to consider is whether you're going for a simple, "Get equal or higher than this number" mechanic, or whether you have a specific target number that will cause a critical hit, or whether it's a mix.

If for example, you have to score at least 9 to hit, but if you get exactly 9 you cause a crit, then:

With D6+x (if x is between 3 and 8) you have a one in six chance of a crit (0.166)

With 2D6 you have a four in thirty six chance of a crit (0.111)

So the probabilities of any given number are much more evenly distributed with just a d6+x mechanic. It's largely up to you to decide whether that's what you want..

In your example, rolling 8 on 2d6 with either a +1/+2 or +d6 bonus I would take the +d6 bonus every time.

Probability of at least 8 on:
2d6+1 = 0.583
2d6+2 = 0.722
3d6 = 0.838 <-definitely more powerful

I'd recommend taking a look at this website as it makes these sorts of calculations fantastically easy: http://anydice.com/

When it comes to surges, with the 2d6+x method you never change the probability of a surge (it's always 0.333), but if you add in bonus dice you will increase the probability of a surge (+0.166 for each extra d6), so that's a choice you'll have to make - whether you want bonuses to affect surges or whether you want them to remain independent of them.

I think you might be overthinking where your randomness comes from. To say that the attack is 2d6, and the armor protects for 1d6, is actually the same as saying the attack is 3d6-7. That is: [2d6-1d6] == [3d6-7] http://anydice.com/program/3f89

Also, well made armor actually is pretty consistent. That's why the medieval nobility considered war to be such great sport, because mostly the crude weapons of the peasants couldn't actually hurt them through their plate mail. So they got to ride around on their armored horses and play whack-a-mole with human lives, at very little risk to themselves. (It's pretty sick, really.)