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Introduction to Each Post in This Series
On Friday (July 23, 2021), I mentioned that I was relearning AD&D 1st Edition (“1e“) with the intention of running it. As I read through the Player’s Handbook (“PHB“), certain mechanics or text will strike me as odd or surprising, but in either case worthy of discussion. In fact, the most surprising thing I’m experiencing is that I’m finding a lot more great ideas in 1e that we’ve since abandoned. I find myself asking, “Why?” As a result, I’ll be writing several posts over the next few weeks. I’m sure everything I’m thinking has been discussed before — sometimes be me — so perhaps my questions have been answered, and my concerns resolved, years ago. My experience with RPGs is relatively limited in scope, having played a small number of games, so I’m sure a lot of what I’m going to say has been incorporated into games I’ve never even heard of. (Some have certainly been addressed by future editions of D&D themselves.) Nevertheless, bringing this directed conversation to the public is new to me, so here it goes.
Posts in this series: | My Playlist | Campaign Settings and Pantheons | Languages | Level | “Dead Levels” | Division of Labor, Distance, and Time | Initiative | Combat Subsystems | Armor Class Ratings | Alignment and Reputation | The Feel of a School of Magic | Boring Magic Items | Ability Score Bonuses and Skill Rolls | The Problem with Democracies | Hitting More Frequently | Encounter Balance and Shooting Yourselves in the Feet |
Armor Class Ratings
If there were a subtitle to this post, it would be, “1st Edition AD&D; where logic goes to die.” I think this post exists just so I can reinforce this crazy rule in my brain, but perhaps many of you reading this have never played 1e (or have forgotten it), so it’s still useful to illustrate a point.
The notion of Armor Class Ratings (“ACR“) adjustments is fascinating and logical.

The idea is that some weapons are better suited to attack specific types of armor than others. For example, the long sword is probably the best weapon a Fighter could carry for a number of reasons, but a morning star works better against a shield (+2 v. +1). Why? Perhaps because when the morning star is blocked, it’s bludgeoning force can transfer through the shield to damage the enemy’s arm. Similarly, a footman’s military pick (+2) can better find the gaps in plate mail than a battle axe (-2). These advantages are reflected in attack bonuses and penalties against ACRs. What do I mean by ACR? You’re going to be sorry I asked myself that.
Your ACR (a.k.a., base AC, AC type) is based on a chart provided below. It ranges from 2 to 10, though in Unearthed Arcana that range is extended down to 0. This is a number distinct from your actual Armor Class value (“AC“). So, if, for example, you’re wearing plate mail, your ACR is 3. Add a shield to that, and it becomes 2. The ACR is the AC the armor would grant on its own before any other adjustments are made; therefore these numbers are fixed as long as you’re using that armor. Your actual AC can be different due to a bonus or penalty granted to you by your Dexterity score, magical influence, or circumstances. So, the Fighter in plate mail has an ACR of 3, but could have an AC of -1. Your ACR, however, is the basis for the weapon-based attack bonuses and penalties for your enemies.
Type of Armor | ACR |
None | 10 |
Shield only | 9 |
Leather armor // padded armor | 8 |
Leather + shield // padded armor + shield // studded leather // ring mail | 7 |
Studded leather + shield // ring mail + shield // scale mail | 6 |
Scale mail + shield // chain mail | 5 |
Chain mail + shield // splint mail // banded mail | 4 |
Splint mail + shield // banded mail + shield // plate mail | 3 |
Plate mail + shield // field plate armor | 2 |
Field plate armor +shield // full plate armor | 1 |
Full plate armor + shield | 0 |
The Downsides
But here’s the thing. First, it’s crazy complicated, both on the DM end and the player end. It’s yet another layer of rules to apply to combat that, sadly, isn’t even included on the Dungeon Master’s Screen. Moreover, players playing fighters have yet another factor in picking what weapons to carry around, and they must be able to think on the fly as to what weapon to use in any given scenario. For example, as stated above, almost every fighter is going to have a longsword (-1 v. plate mail) or battle axe (-2 v. plate mail) as their primary weapon, but will also need a dagger (-3 v. plate mail) or short sword (-2 v. plate mail) for close-quarters combat, and some form of ranged weapon in case there’s a lot of distance between them and their enemies, the best against plate mail being the long bow and heavy crossbow (+0 v. plate mail). Because of ACR, the fighter will also want a footman’s flail, military pick, or two-handed sword (each +2 v. plate mail) strapped to their back in case they run into an enemy wearing plate mail, but they also want a spear in case they charge, or are charged by, an enemy. Did I mention that a Fighter is proficient in only 4 weapons until 4th level (PHB, 37)? Have we gone over encumbrance rules yet (PHB, 101)?

Second, the basis of the rule is logic, but that logic quickly breaks down. As you can see from the chart, the base AC for splint mail and a shield is the same base AC for plate mail without a shield. So why would the morning star react to both the same way? Without the shield, the morning star shouldn’t get any sort of bonus, so as complicated as this rule is, it should be even more complicated, instead tying ACR bonuses and penalties to the specific armor used rather than on the numerical AC they inherently give. That is, instead of saying a morning star grants a +2 against any combination of armor that would, unadjusted, grant an AC of 2, the rules should say that a morning star grants +2 against any opponent relying on a shield regardless of what else they’re wearing. Maybe. If I really thought about it, an even more complicated rule could be appropriate. Fortunately/unfortunately, logic cedes ground to abstraction, because otherwise, well . . . .

So Why Am I Going Use Them?
First, I want the full 1e experience, so I’m going to use this in my game at least to start. Second, I’m optimistic that this won’t be much of an issue because this applies only to enemies using armor. Monsters that don’t wear armor aren’t considered to have ACRs (DMG, page 28). Their AC is what’s needed to properly balance the system. At least that’s what the creators claimed.
Third, let me tell you another story . . . .
Because of my 23-year hiatus from D&D, I completely missed 2nd Edition D&D. I’ve played three sessions of it since returning to the game, once for two hours, and then twice in successive weekends as part of a single adventure (probably about 5 hours each session IIRC). In the first of those latter two sessions, the DM (Erik) game my bard a wand of magic missiles. He randomly rolled the number of charges for me, and it was ridiculously high. There’s no way I was ever going to run out of magic missiles. So, every time I tried to use my rapier, cast a non-healing spell, or use any non-standard attack, the entire table said, “No! Use the wand!” Thereafter, the game bored me, and Erik actually apologized. He thought he was doing a nice thing but wasn’t thinking about how it would impact the way I like to play.
ACRs make things a slight bit more interesting. A party may insist that the Fighter always swing a longsword, but sometimes it won’t be the best option. As a player, swinging a morning star isn’t very different — roll a d20 to hit, and if you do, roll damage — but there are other useful things a character can do in combat. If the longsword isn’t as valuable as grappling, knocking a bookshelf over, or swinging from a chandelier to kick an enemy prone, then a Fighter will no longer be a one-trick pony. Combat modifications like ACR will leave a player looking for the right tool for the job. Assuming the system turns out to be workable, wouldn’t that be more fun?
That brief shot of his left eyeball is solid gold.
Follow me on Twitter @gsllc
Dungeons & Dragons is a trademark of Wizards of the Coast, LLC, who neither contributed to nor endorsed the contents of this post. (Okay, jackasses?)
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