Design & Development: Revisiting Armor as Damage Reduction

While working on Cowboys & Cthulhu, I had a thought concerning armor and Armor Class.

At first I was going to just do it like in Dungeons & Delvers, where you slap on an armor category (light, light reinforced, medium, etc) and get an AC bonus and some DR. Normally you don't see armor very much--if at all--in the western genre, guns and all, but there are a lot of Lovecraftian horrors prowling the landscape that it could be useful against. 

While guns have a high AP value, preventing armor from soaking damage if you get hit, it would still be effective in preventing you from suffering damage in the first place, which doesn't make much sense. So, I thought, instead of traditional AC, I could just go with granting Damage Resistance, like we did way back when we were first playtesting Dungeons & Delvers.

Here your "Armor Class" was just 10 + your Dexterity, and anything you got from shields. Magic might also have contributed, but if it didn't effectively provide cover, it just bumped up DR. This started at 1 for a gambeson, and scaled up to 8 for plate (effectively, the AC modifier the armor would have granted became DR).

The problem was that anything with even one point of Armor Penetration completely negated your gambeson, and if you got ahold of plate (DR 8) then you were largely immune to many attacks, especially if they only inflicted a single die of damage and didn't have that much of a modifier. The reason we changed this was when the plate-wearing cleric was dealing with a dozen or so lizardmen: they could hit him easily enough, but at best only dealt one point of damage, and that's if they were lucky.

So we pared it down and reintroduced AC modifiers: a gambeson gave you +1 AC and 1 DR, and each subsequent type of armor added one to both, up to plate, which was +5 AC and 5 DR. This worked out okay, but while working on Red Book we ultimately shifted to a more traditional approach, with armor granting the AC modifier you'd expect, while also providing small amounts of DR (1-3, depending on if the armor was light, medium, or heavy).

But for C&C I'm thinking of going back to pure DR, even scaling it back up to 8. Partially this is because guns have a decent AP value, and partially because of an idea I had, where you deal bonus damage if your attack exceeds the target's AC by x points, reflecting your attack being more accurate, you hitting a more vulnerable spot. There are three ways I see it playing out, but some things to keep in mind.

First, attack bonuses in C&C will be more frequent than in D&D: a gunslinger gets +1 to hit every level (as opposed to effectively +1 every five levels that fighters get). Preachers would be a bit slower, and sorcerers slower still, but everyone gets it because it's assumed that everyone is at least practicing shooting and stabbing things, since you can't always rely on magic. You can't even always rely on guns, so melee weapons will be far more commonplace.

Second, there's a Ganging Up mechanic. The first attack against a given target is made normally, but successive attacks made against the same target get a cumulative +1 bonus to hit. This represents the target having trouble evading attacks from multiple attackers. Unlike D&D, where it only granted a hit bonus, now you'll want to coordinate your attacks to help someone get a damage bonus, too.

Finally, classes will also get a scaling Defense bonus, representing them just getting better at avoiding danger. It won't be at a one-for-one rate, so Attack bonuses will make a difference. It won't be like 3rd or 4th Edition, where things pretty much scale at the same rate, so what's the point, really? Maybe +1 every 3-5 levels, depending on class. Not as easy to boost, but then cover will be important, as well as using unspent Action Points to boost Defense for a bit.

So, the current models I've cooked up are:

• Option 1: You deal +1 damage for every x points you beat their AC, meaning this can trigger multiple times. The hope is that it will make combat just a tad swingier. But, we'll see.
• Option 2: If you beat the target's AC by 5 or more points, double the weapon's damage dice. So 1d4 becomes 2d4, 1d10 becomes 2d10, and 2d6 becomes 4d6. A kind of "soft" critical hit, as it were. This one I like because it's relatively simple, and makes the weapon choice really matter. Downside is that damage could spike quite a bit, though not as bad as option 3...
• Option 3: Beating the target's AC by 5 or more points doubles the damage, and for every 5 points beyond that you up the multiplier by 1. So, beating by 5 is x2, while beating by 10 is x3. 

What I like about options 2 and 3 is that it makes combat swingier, and could fairly easily solve the issue of higher DR values grinding combat to a halt (especially true in the case of option 3). This could be very helpful if I wanted armor to provide way more DR, like a gambeson doing 3 or even 5 points of DR (but then guns would need AP values of 5 or more, and then I think it gets silly). Option 1 would be less swingy, less likely to screw over players, but higher DR could be difficult to overcome without it.

Have to play through a simple adventure and see how this plays out. Specifically whether the players get one-shotted, breeze through their foes, if it's too complicated or time consuming, what with potentially having to do more math. Which means we'll need to do it three times, at the least, once for each option.

Assuming any of these methods actually work, this could easily be applied to D&D, though magic could result in a pretty hefty DR, and weapon Armor Penetration isn't nearly as high, so the bonus damage ratio might need to be adjusted to something like every 3 points, or even 2. Definitely wouldn't want to do 1 for 1, because that would get pretty crazy. 

Of course, all classes would get a scaling Defense bonus, too.

Oh, for effects that require saving throws, you would just reverse it: failing by 5 (or 3 or 2) points also causes you to take bonus damage. Or, if you want to get really crazy, you modify it like this (using one of the sorcerer spells):

SHRIVEL
Action Points 8
Sanity 1d4
Range 30 feet
One creature within range must attempt a Constitution save. On a failure they suffer 2d6 damage, or half damage on a success. Any WP damage inflicted is Drained.

• +1d4 Sanity: The damage is increased by 2d6. You can continue losing Sanity, increasing the damage by 2d6 each time, but the total damage dice cannot exceed your level.
• +1d4 Sanity: The range is increased to 60 feet.
• Failure (5): The target suffers an additional 1d6 damage.
• Critical Failure: The target is so wracked with pain that they are Slowed 2.

Failure 5 and Critical Failure would be clarified in a previous section, where Failure 5 means this effect triggers for every 5 points they fail, and Critical Failure also triggers on a saving throw of nat 1. This would be nice, given that weapon attacks have critical hits, while spells don't.

Curious if other games, namely d20 ones, have something like this. I know 3rd Edition had optional rules for armor-as-damage-reduction, but I don't recall anything for scaling up especially accurate attacks. Would be nice to see how someone else did it, as well as obvious pitfalls/drawbacks I'm not realizing.