Gelatinous Icosahedron

 Combat offense in D&D is modeled with attack rolls, using d20, modified by class and level plus ability score modifiers or by creature Hit Dice, in either case representing some combination of skill and physical power, and by a damage roll, generally representing the amount of force brought to bear on a successful attack. It can be a wonky system, and sometimes counter to our intuitions of how combat and bodily injury actually work, but it serves its purpose well enough in the game. Defense in D&D combat can be even wonkier and less intuitively satisfying. Like offense, it's broken down into two primary components, Armor Class and hit points. Both, conceptually, serve the same broad function, which is to represent the avoidance or reduction in severity of bodily injury, but they do so in ways which are mathematically distinct and very different intuitively.  Armor Class is the more intuitively comprehensible of the two, though it itself represents two semi-distinct co...

 In a recent post about things I like and don't like about B/X D&D, I mentioned in passing that I don't see initiative as a strictly necessary rule in D&D combat. Another blogger has suggested I expand on that thought, and so in this post, I articulate my case for why initiative is not a necessary component of a functional D&D combat sequence. Initiative, as I see it, can be a useful tool to impart some order and structure to combat. Insofar as it models any aspect of real combat in the game, though, it doesn't do it particularly well. Maybe not particularly badly either, but it's a simplistic and formalized rule for a very chaotic and unpredictable situation. Depending on particular circumstances and how one rationalizes it, it can either make sense or defy sense. It implies that whoever has initiative, if his attack roll succeeds, does all his damage before his opponent can attack in return, so the opponent might be killed before he can even attempt his ow...

When it comes to fighting without weapons, D&D tends to go a bit insane. Besides often coming out overly fiddly and complex, subsystems for unarmed combat tend to mesh very poorly with the standard (armed) combat rules. Game designers, it seems, have tried to model a set of Hollywood fight tropes which don't fit well with the abstractions and assumptions of D&D combat. Consider, for instance, the ever-popular notion of knocking out an opponent with a single punch. In a game where clubs and maces can only whittle away the opponent's hit points, a rule allowing knockout punches produces results that are often counterintuitive, if not outright ridiculous.  I've made my own attempts on more than one occasion to construct a set of viable grappling/unarmed combat rules, but now I'm coming at it from a very different angle. The main problems with unarmed combat subsystems are A) treating armed and unarmed combat as fundamentally distinct from each other when in most re...

 Taking a break from the Monsters A to Z for some pondering on what you can do with some new old-school friendly combat mechanics. One of the strongest signs that Old School gaming is not simply about nostalgia is the extent to which old schoolers have embraced ascending Armor Class, in conjunction with class-based attack bonuses, over the old descending-AC-and-attack matrix or THAC0 system. It doesn't just streamline the math and eliminate a whole layer of fiddliness, though, as much as those effects are to be hailed. Within the ascending AC and attack bonus framework, you can do some pretty cool things that would have required some real mental gymnastics in the traditional system. The magic of this approach really lies in the use of an attack bonus stat rather than lines and columns in an attack matrix, which allows everyone to use the same target number for the same target.  To illustrate the point a bit more clearly, consider a 5th-level fighter and a 1st-level magic-user ...

 When it comes to doing better in combat, there are a few ways a character or monster's battle effectiveness can be scaled up. For purposes of this post, I'm talking about the character or creature's actual inherent combat effectiveness and improvements in combat ability from gaining levels of experience, not bonuses from magical weapons and the like. Better attack rolls: The character "hits" more often. Each 1 point of attack bonus or decrease in THAC0 results in 5% greater average damage per round. The average damage per successful attack and the maximum possible damage in a round are unchanged. This is how it works for all characters in B/X D&D. More damage: Damage per successful attack is augmented, either by adding a flat number or by increasing the size or number of dice rolled for each attack. The chance to succeed at an attack is not affected. This method is used in BECMI's Weapon Mastery rules and to a lesser degree in AD&D's weapon spec...

 D&D combat is weird when it come to animals (and animal-like fantastic creatures like griffons and owlbears.) Actually, it's weird in several ways. First is the breaking of combat abstraction in creatures with multiple attacks. It's pretty well established by now that, for a character, one attack roll does not equal one swing of a sword. It represents the cumulative effects of ten seconds (or a full minute, in the case of AD&D) of thrusts, jabs, feints, parries, and such. Even the damage rolled need not come from a single wound; it could be several small wounds. For a while I struggled with the idea of a single creature making multiple attack rolls per round, but I've come to the conclusion that multiple attack rolls, in and of themselves, don't violate abstraction. It's just a particular mathematical relationship between offense and defense and damage, which need not imply a particular number of specific strikes any more than a single roll would. So a bear...

 Way, way back in the long-ago days of the mid-80s, I was introduced to D&D through a copy of the Moldvay Basic Rules and the accompanying module B2: The Keep on the Borderlands. Before I ever worked up the courage to ask my siblings if they might like to play this game, I had read both books cover-to-cover at least a dozen times and thumbed through the most interesting bits still more, and they left some impressions. One of those impressions was a sense of scale regarding hit points. The average starting player character might have 7 or 8 if he were lucky, but maybe as few as 1 or 2 (though I did take to heart the suggestion that players be allowed to re-roll at 1st level only if the dice came up 1 or 2.) Lots of 1st-level NPCs had hit points below average for their class's Hit Die -- I recall plenty of Keep guards manning the walls with 3 or 4 hp. NPCs of 2nd level seemed quite tough with 7-10 hp or so, and those of higher levels with hp totals in the teens were real badasse...

 The abstract nature of classic D&D combat doesn't lend itself well to calling discrete moves and maneuvers. A lot can happen in a 10-second combat round. Combatants trade feints and parries, with weapons, shields, and body parts. They grab and push and trip. They try to pull dirty tricks like dust in the eyes or stomping on toes. They stumble, maybe fall down, maybe get back up. They may get dazed or stunned momentarily, but shake it off in the same round. All of this is distilled down to an attack roll and possibly a damage roll, because it's assumed the ultimate objective is to hurt the opponent. The specifics of how you get to that point are descriptive only, and don't need to be mechanically codified. I'm not saying you absolutely can't or shouldn't add mechanics for called shots, parries, trips, throws, dirty tricks, and whatnot, but it all runs counter to the idea of abstraction, that the actions of a round ultimately boil down to how much damage is d...