Armor Class vs. Damage Reduction - Your preference

[RangerWickett]

So first you calculate the vector angle at which the attacker can hit the target. A halfling that is adjacent to a human might fill up 45 degrees of his field of vision, as opposed to 20 degrees farther away.

Then determine whether the attack is a radiating line like a rapier, or a plane segment like the path cut by a sword.

If the former, multiply the attacker's accuracy rating by the percentage of 180 degrees that the target takes up.

If the latter, program a 3D graphing calculator to track the intersection swath along the possible paths of the swinging weapon. Multiply the attacker's accuracy rating by the ratio of a hemisphere's volume.

Next, plot a random table with hit locations based on the odds above. Make the attack roll, and based on the table determine if it misses, and if it hits what location.

From there, the rest is far less straightforward. It'll all be detailed in my upcoming book.

 

[TerraDave]

In principle, I agree with you that Armour-as-DR is somewhat more realistic.

In practice, I've found that Armour-as-DR creates a lot of problems (even in games designed to use it from the outset). Armour-as-AC just works better.

So I'll take Armour-as-AC, please.

YMMV, of course.

This, BUT

I used to prefer AC to DR but then I played Savage Worlds. Everyone has natural DR in the form of their Toughness attribute with armor adding to it. This increases realism and allows for Savage World's best feature, no hit points (or very little hit points anyway). Since your not tracking every graze and scratch, DR ends up being much easier to do.

Sure, if its a totally different game, then it can work! I think the toughness save in Mutants and Masterminds works in a similar way.

 

[Agamon]

I'm with the folks that prefer simplicity over realism. Abstraction is fine, and in fact better for allowing wider range of description of a blow. I like WHFRP2 and Hackmaster, but I still prefer armor as AC.

 

[Smoss]

Like the OP, I started in 2e and went to 3e. I was building my own systems before 3e came as 2e didn't do what I wanted.

I started with multiple ACs (armor Class and Defense Class). Similar to the direction SW Saga and 4e went. This worked, but wasn't good enough.

When 3e came, I liked it a lot. I enjoyed DR and tried armor as DR. This had issues but I liked the idea.

My final solution was a damage threshold that armor adds to (Base threshold based on CON). It works very similar to Savage Worlds when it comes to damage. Beat the threshold (Do enough damage) and you actually hurt the person. Do not and you do not. (I also eliminated hit points. I hate hate hate HATE bookkeeping. Minions was the one thing I really liked about 4e, much like mooks in Savage).

I've since tweaked my system to be as realistic feeling as I could with as little math and such as possible for speed. It is as close to perfect for my use as I can get it without either massive math or sacrificing brutal realism. (I also found a way to have fast and easy lopping off of limbs and such too. So yeah, battles can be gruesome)

Smoss

 

[timASW]

armor as AC sucks. I've houseruled it away since AD&D 2e and the method hasnt changed much in all those years because its simple and easy.

Defense score = 10+Dex+shield+BAB
DR= armor + CON bonus.

Attack roll that beats the defense score hits and does damage per the weapon type plus the amount by which the attack roll beat the defense score. (sometimes i use 1/2 that amount, depends on how lethal i want combat to be).

Critical hits ignore DR entirely.
Con no longer adds to HP. (often HP are also reduced, again depending on how lethal i want it to be.)

Its simple, easy and gives me plenty of dials to turn depending on the feel of the campaign i want. I've also gone back and forth between the defense score being a static and being an opposed attack roll. I've found I slightly prefer it as a static # but I can go either way depending on how the players vote.

 

[3catcircus]

armor as AC sucks. I've houseruled it away since AD&D 2e and the method hasnt changed much in all those years because its simple and easy.

Defense score = 10+Dex+shield+BAB
DR= armor + CON bonus.

Attack roll that beats the defense score hits and does damage per the weapon type plus the amount by which the attack roll beat the defense score. (sometimes i use 1/2 that amount, depends on how lethal i want combat to be).

Critical hits ignore DR entirely.
Con no longer adds to HP. (often HP are also reduced, again depending on how lethal i want it to be.)

Its simple, easy and gives me plenty of dials to turn depending on the feel of the campaign i want. I've also gone back and forth between the defense score being a static and being an opposed attack roll. I've found I slightly prefer it as a static # but I can go either way depending on how the players vote.

Regardless of whether you use AC, DR, Active Defense, the single biggest factor in making things simple is to end the AC, BAB and hit point arms race - it looks like you've limited your bonuses to both defense and DR - do you stack any bonuses from magic, natural armor, etc.? I also like that it looks like you limit damage bonuses to only the amount you succeeed by - do you stack any magic bonuses or STR bonuses?

 

[Li Shenron]

Maybe I would prefer worn armor as AC bonus (representing covering weak spots) and natural armor as DR (representing tough hide of certain creatures), but I've never used this, just armor as AC because of its simplicity.

 

[Hand of Evil]

Run me over because I am in the middle of the Road.

It comes down to the type of game you are running, sometimes armor = AC is a good thing and sometimes DR is a good thing. Example for me, a fast pulp type game, where armor is not that common, I could see DR as the best way to handle it. A game of fantasy combat and tough monster, with lots of weapons and armor, AC. You have to look at flavor and balance.

 

[Jhaelen]

My favorite combat system is still the original Runequest one. Imho, it manages to find the happy medium between realism and playability. Incidentally, it models armor as DR, so that's my preference, I guess.

 

[shadowgames]

I prefer armour to have damage reduction rather than a set number to beat. I quite like the way armour is dealt with in Song of Ice and Fire roleplaying game.