Descending Armor Class

I hail from the era of the post-3e consensus, where it is a given that descending armor class is unintuitive and dumb, while ascending armor class is simple and pristine. The orthodoxy on this is rather ubiquitous. I’ve been hard pressed to find any modern TTRPG that embraces the concept, and even the OSR gang tends to toss the idea overboard when designing their fantasy heartbreakers.

The origins of descending armor class are murky, though it’s been well explored in blogs that actually know what they’re talking about. The apocrypha suggests that it was built from Arneson’s experience with naval wargaming, where a ship with 1st class armor would be harder to sink than 2nd class armor. While that is likely the origin of why we call it “Armor Class,” the choice to descend appears to be based more on Gary’s opinion on the elegance of the math involved.

Elegance

Putting aside the math for a later date, one may ask if there are any advantages to descending armor class, at least in the context of designing new or derivative rules for TTRPG combat.

I can see three.

First, it’s compatible with TSR-era modules. When 25 years of D&D material uses descending AC, using that expected number keeps DMs from having to do quick conversion or scribble in the margins. There’s value in being able to run the old stuff right off the page without much adjustment, even if the math gets a bit off between the early editions.

Second, it evokes an old-school feel. This is admittedly trivial, but it’s not to be discounted. Much of a game’s tone and style is brought forth from the decisions a designer makes in crafting its ruleset. There’s nothing that says ‘old game’ like holding onto an antique like descending AC. It’s like putting a spittoon in your bar or using neon pink in your cyberpunk art; the aesthetic is in service to the ideal.

Or like putting this style of art in your AD&D clone.

Third, a bounded range that terminates at zero provides a floor. AC 0 stands as a solid barrier between a character that is just well protected or quick and one that is armored by magic or by other extraordinary means. When crossing that threshold of zero into the negative, PCs find themselves fighting something otherworldly. Those monsters are a mathematical indication that you have entered the Upside Down. This is compared to something like 5e, where the barrier of 20 is rather soft; the difference between an enemy with AC 19 and AC 21 is just a small bump in difficulty, but the difference between AC 1 and AC -1 is a line between the mundane and the mythical. This Mythlands post does a great job of digging into the idea. 

These advantages suggest to me that descending AC should hold at least some esteem in modern old-school creations, but it’s generally rejected unless the work is trying to ensure compatibility. The reason for this has nothing to do with AC moving south, but instead is due to the mechanism for how you hit it. Tables and wonky formulas are what get brought up when descending AC is derided. We'll look at that problem next time.

Planescape: Setting and System

Planescape is, by far, the most interesting fantasy world I’ve ever stumbled across. The later editions of D&D offered only the barest glimpse of this setting, with descriptions of Sigil, the City of Doors, the otherworldly Outer Planes, and the city’s enigmatic ruler The Lady of Pain.

When I finally dug deep enough into the historical strata to hit the rich vein of the mid-90s, I found a treasure trove of lore within the Planescape campaign books and accessories. TSR had invested much into their creation, detailing everything from apothecaries to crime kingpins, all wrapped in a bizarre shell of an impossible dystopian magicpunk setting. It had a feel and tone that I had only seen in novels like Perdido Street Station and Neverwhere, with a clash of cockney slang, philosophical war, and easy death. To sweeten the pot, a great deal of that lore and tone was injected into the only video game based on the setting: Planescape: Torment.

The best book I've ever played

By the time I’d decided to run the setting, the 5th edition of D&D was in full swing. The setting was all I cared about, so the system got the boot. I ran that world with 5e and had a blast doing so, but found that I wasn’t getting the tone that I had expected. Everything was combat and frantic challenges. By scraping the system it was built for, I had changed the nature of the setting.

5e’s triumph is that it makes every character feel like a unique set of skills and abilities. That character never feels like anything other than the main character, even when you’ve got another four main characters wandering about with you. The world is your playground, and the setting is the backdrop to your character’s superheroic feats and inevitable victory.

That is not Planescape’s vibe. Planescape is about fantastic places and people, but it shows those places through the lens of the ordinary. It’s where an angel and demon may share a beer, but they do so in a dive bar after having completed whatever humdrum tasks make up their daily life. Much of that life is cheap, with a major part of Sigil being depressing slums where surviving another day is the only achievable goal. It’s a dog-eat-dog world, made for a TTRPG ruleset where not getting eaten was a major accomplishment; 5e just did not translate well to that ethos.

The vibe

 

Planescape was built for 2nd Edition AD&D, with all of its quirks and assumptions about the type of characters you would have. Those characters would start off relatively powerless and certainly poor. They had to scrabble for every opportunity, and they had to be played cautiously and wisely to make it out of 1st level. A 2e character has a weapon, maybe armor, maybe a spell or two, a few hit points, and (if your DM decided to include them) a set of skills. They didn’t parade around Sigil as lords of their domain; they survived Sigil by being just a bit quicker, smarter, stronger, or luckier than the berk next to them.

This is perhaps too many words to say that I like squishy and desperate characters in my dystopian settings, but hopefully provides context for why I started my latest Planescape campaign in 2e.

Why AD&D 2e?

Is that zero in the word "OPP0NENT?" 

In short, I wanted to run Planescape. That’s a stupid reason to learn and run a 35 year old TTRPG from a defunct publisher, but it was the inciting incident. That initial interest in 2e was spurred on by growing dissatisfaction with WotC over the past few years, the underwhelming 5e version of Planescape, and seeing what the OSR community had to offer. The road toward cracking open the 2nd Edition AD&D core books had been laid.

Some context: I missed all of AD&D and 3rd Edition. TTRPGs weren’t in my wheelhouse during those years, and aside from having used those systems in the CRPGs from the era, they were opaque to me. I started in 2008 with 4th Edition, mostly due to the excellent podcasts WotC was putting out with the Penny-Arcade crew (they’re still online and worth a listen). Saying that you started out in this hobby with 4e is a bit like telling someone that you got into Star Wars by watching the Holiday Special, but it is what it is. We ran that edition happily for four years until going all in on the D&D Next playtest material, then lived in 5e for a solid decade. That’s all to say, I don’t have the old-school chops of the venerable grognards; I came to AD&D with a very different mindset.

My mindset

 

I suppose it should be little surprise that someone raised in the offal of 4e would gravitate to the other ‘bad’ version of the game. 2e is generally viewed as the corporate version of AD&D, the one without Gary Gygax, made to cut the old man out of the story, remove the stuff that angered the fundies, and shore up dwindling book sales. I did investigate 1e AD&D, OD&D, B/X, and their various retroclones. The internet made no qualms about their superiority, and they have a great argument there. For what these earlier editions do, they’re brilliant. They create a foundation upon which a very particular gameplay loop can be structured, with the dungeon as its crown jewel. The challenge was, I wasn’t looking to send my players into caverns deep and dark; I wanted a system that would blend the old-school, dungeon-delving rulesets of those editions with the modern focus on character-centric, story-based roleplaying. I also wanted better formatting. I was in luck, as they released that game in 1989.

And in 1995 with worse art! And in 2013 with a fancy cover!

 

 

2nd Edition AD&D is something of a beautiful hodgepodge. It’s designers were extremely knowledgeable about what had come before and loved it. Its lead and technically only credited designer, Zeb Cook, literally wrote the X in B/X. They were also given a mandate by their corporate overlords to keep the thing compatible with 1e, so in essence it is the ‘same game’ with the same spirit, and as a result it carries over many of the frustrating idiosyncrasies which later editions would expunge and OSR successors would smooth out.

Yet, it’s also modern in many of its assumptions. By 1989, the module-as-a-story concept was established, while the multi-level dungeons and deadly funhouses of earlier works were no longer the main point. This edition’s focus on completion of the adventure and good roleplay to earn XP, its ability-check-by-another-name skill system, and its completely modular design were built for the types of adventures that TSR wanted to produce, where hard-bitten mercs could rob the temple or intrepid heroes could save the kingdom within the same ruleset.

If you’re reading this and are well versed in the OSR community, you may be shaking your head, making tsk tsk and tut tut noises, and saying “If you wanted that you should have just picked up [insert OSR product]!” Yes, I’m positive that something like Dungeon Crawl Classics or OSE would have scratched the itch without all the pain of learning this crumbling and forgotten fossil. But then I couldn’t have run the original Planescape material straight from the books, and that was a major selling point. Also, I found that I really like descending AC, and if you can point me to an OSR game that retains it without matrices, I’ll thank you.

The 2e Primer

If you’re here to just grab the file, it’s here.

If you’d like to understand why I made the thing, keep reading.

While this edition is better organized than the earlier games, it’s still a mess. Sometimes rules get tables, sometimes rules are buried in paragraphs, and some rules were forgotten completely, only to surface years later in an accessory book, or else are spread over multiple chapters and never reference one another.

Learning this system can be exhausting, as you can never be sure what you missed or if you’re even playing correctly. That’s not unique to this edition, even 5e has its moments of ‘oh look at this rule they tucked away,’ but in 2e it’s ever present. I was learning the system in order to teach it to a group of players whose experience with D&D goes back no further than 3.5, and I knew I would be their only lifeline to understanding its mercurial nature.

I searched the internet for a good quick guide, an overview, a cheat sheet, anything that could give me a roadmap, but there really wasn’t much out there. So I did what I usually do when learning any overly complicated and occasionally contradictory collection of information: I took notes.

Those notes eventually coalesced into a guide, and within a couple months of writing and play, I had something I found useful. I thought others might, too. I downloaded Scribus, edited the thing into something readable, and now it’s The 2e Primer.

If you see errors or places where improvement can be made, please share them. I’d like for this document to be the tool I couldn’t find when I was searching for help; anything you can offer toward that end would be appreciated.