Toward a History of RPG Mechanics - Part Two: Chainmail and Original D&D

Last time, we started with an overview of Perren and Gygax's Chainmail, a medieval miniatures battle game that evolved into D&D. To recap, the system consists of four subsystems, three of which interact: a mass battle system, a "Man-to-Man" system for smaller battles, and a system for handling combat between 'fantastic creatures' (including wizards, heroes, etc.).

The "Man-to-Man" combat system is the portion that Dave Arneson used for his early Blackmoor campaign. The core of the system is expressed in the "Man-to-Man Melee Table" and another table, titled "Individual Fires With Missiles".

The melee table cross-references 12 different weapon types against 10 armor types (two of which are purely for horses). This gives a number, which the attacker must roll equal to or greater than on two six-sided dice in order to kill the defender. The lowest number is 5, for a mounted man with a lance against any armor less than mail, or for a two-handed sword wielder against an opponent in mail; the highest is 12, which shows up only for defenders in plate armor, or for a horse with barding.

The missile table is similar - however, here we see an armor class number, ranging from 1 to 8. What these armor class numbers correspond to is not explicitly given, but the safest presumption is that they are meant to be the same armors shown on the melee table, so class 1 would be "no armor", while class 8 would be "plate armor and shield". The horse armor columns are explicitly labeled, rather than being given as classes.

Each cross-referenced entry on the missile table consists of three numbers, for short, medium, and long ranges of the weapon in question. (These are simply divided in thirds, so, for example, the short bow with a 15" range has a short range up to 5", medium up to 10", and long to 15".) We also see an addition of a "cannot kill" result in this table.

Mounted troops gain an advantage in melee, getting +1 to their roll, while foot troops fighting mounted troops are at -1. Attacks from the rear also grant a +1.

The benefit of first blow (that is, "initiative" in the RPG sense) is gained by the one who initiated combat (by moving into melee range), unless the opponent has a weapon which is "two classes higher", or the defender is fighting from above (e.g., atop a castle wall, rampart, up stairs, etc). The weapon classes are set on the basis of length, so that a defender with a significantly longer weapon can gain initiative.

Attacks from the rear prevent the defender from striking back on the first turn, and cause the defender to automatically strike last on the second turn. (It may be appropriate to note here that the rules actually say 'round', although 'turns' are referenced in the mass combat system. Nowhere is a distinction made between these in Chainmail, and a 'turn' is defined to be about one minute of battlefield time, making it the same as an OD&D 'round'.) Attacks from the left flank cause the defender to strike last on the first turn of melee.

After the first turn, whoever struck first before continues to strike first (static initiative!) unless their opponent has a weapon two classes higher or is above them. Of course, since the one initiating combat strikes first unless one of these two is true, this basically boils down to "if the defender automatically lost initiative because of being attacked from the rear or flank, reassess initiative once their forced loss ends" plus "if movement in combat places the defender above the attacker, the defender then gains initiative".

Weapon class comes into play in some more interesting ways as well. This gets complicated, so I'm going to quote:

"4) a. For any weapon 2 or more classes higher than the attacker the ability to parry does not exist.
b. For any weapon 1 class higher to three classes lower than the attacker the defender may parry the blow by subtracting 2 from the attacker's roll, but he has no counter blow.
c. For any defender whose weapon is four to seven classes lower than the attacker, the defender has the option to give the first blow OR parry the attacker's blow, by subtracting 2 from the attacker's roll. If the attacker equals the original requirement for a kill the higher weapon breaks the defender's weapon. If the parry is successful, the defender gets one counter blow.
d. For any weapon whose class is eight or more classes lower than the attacker, the defender gets the first blow and may parry the second or strike the second. He subtracts one for the parry and a roll equal to the original kill requirement breaks the weapon. (Pikes, spears or lances of the attacker do get the first blow over lower class weapons if there is a charge. Here the length of the weapon prevents the defender, even with his lighter weapon, the ability to get the first blow.)"

A couple of paragraphs later, we have: "A man wielding a weapon four classes lower (1 vs. 5, 2 vs. 6, and so on) strikes two blows during every melee round. If a man has a weapon eight classes lower, he will strike three blows during every melee round."

Combined with the above, we can put this into chart form, using A for the attacker's weapon class, and D for the defender's:

D >= A+2: defender strikes first, but cannot parry

D <= A-4: defender strikes first and gets two attacks, but may give up the first one to parry, giving the attacker a -2 on their attack. If they do so and fail to parry, they lose their chance to attack at all.

D <= A-8: defender gets three attacks, with the order of attacks going D, D, A, D. The defender may give up their second attack to parry, giving their attacker a -1 on their attack; it's unclear whether they still get the third attack in this case.

otherwise: defender may choose to give up their attack in order to parry, giving the attacker a -2 on their attack.

For further edification, here are the weapons and their classes:

1. Dagger
2. Hand Axe
3. Mace
4. Sword
5. Battle Axe
6. Morningstar
7. Flail
8. Spear
9. Halberd or other Polearm
10. Two-Handed Sword
11. Mounted Lance
12. Pike

Those who are intimately familiar with first edition AD&D may be noticing something here: namely, the "weapon classes" here are fairly similar to the "weapon speed factors" of that version of D&D! The specific rules even bear some similarities (especially the use of 4 and 8 factors difference as "key points"), although AD&D1 only brings weapon speed in when initiative is otherwise tied.

This is a fairly sophisticated system overall, taking in weapon length and speed in an interesting way, and giving an option of fighting defensively through parrying. Small weapons are very fast, but are also less effective at parrying more massive weapons. Longer weapons can give the first strike to a defender, but are also slower, which can give reason for carrying multiple weapons, such as a polearm or spear wielder carrying a dagger or sword. The possibility for lighter weapons to break on a parry also encourages this.

In D&D, this system was the one originally meant to be used. In light of that, certain things about original D&D make more sense:

First, adjustments to attacks were small. A character could gain a +1 or -1 to missile attacks from Dexterity, but that was it. On 2d6, however, that +1 or -1 is much more significant than with 1d20! A +1 magical weapon was quite powerful, and the largest bonus from a magical weapon in OD&D was +3 (and bonuses this high were almost exclusively against a particular opponent type, such as a Sword +1,+3 vs Trolls).

Second, OD&D contains no initiative system at all. As we've just seen, Chainmail had a fairly sophisticated one... but it still left a lot of questions open, such as how initiative should be handled for opponents who have no weapon! Thanks to its origins as a mass combat system, Chainmail also separated movement order from attack order, except in the case of units doing split-move-and-fire, or taking pass-through-fire during movement. Missile fire and melee were also supposed to be resolved as separate steps. This continued to be the case in many RPG combat systems for quite some time.

Of course, instead of a hit being a kill, OD&D added the concept of hit points. In the original game, all hit dice were six-sided, which led to some quite odd progressions. For example, the magic-user's hit dice advancement in OD&D looks like this:

Level: Hit Dice
1: 1
2: 1+1
3: 2
4: 2+1
5: 3
6: 3+1
7: 4
8: 5
9: 6+1
10: 7
11: 8+1

Upon advancing a level, the rules did not make it clear how new hit points were to be established. Would a magic-user advancing from level 1 to 2 simply add 1 hit point to their existing total? For advancing from 2 to 3, should they then remove that 1 hit point and add the result of a die roll in place? These would seem to have some logic, but, from the evidence of modern re-creations such as Swords & Wizardry and Delving Deeper, it would seem that common practice was to re-roll hit points at each level completely, but continue to use the old hit point total if the new one turned out to be lower.

A 'hit' in combat did 1d6 hit points of damage instead of scoring a kill - hence one's hit dice was approximately how many hits it would take to kill them, on average (excepting those with high or low Constitution adjusting their hit points per die). Speaking of that, as with attack adjustments, hit point adjustments for Constitution were kept small - no more than +1 or -1 per die.

The familiar d20-based system for attacks was present in OD&D, but was marked as the "alternative combat system", for those who did not have Chainmail. Here we see the familiar D&D armor class system, with AC 9 being "no armor or shield", and AC 2 "plate armor & shield". In spite of being "alternative", though, this quickly became established as the standard D&D combat system, and is the system used in all subsequent iterations of D&D.

Speculation here: I would guess that D&D's sales well outstripped those of Chainmail, and thus, most players were actually using the "alternative" system. Indeed, in an FAQ for D&D presented in issue 2 of TSR's official newsletter The Strategic Review, it is said that "it is suggested that the alternate system in D&D be used to resolve the important melees where principal figures are concerned, as well as those involving the strong monsters". Thus, at this point ("Summer 1975", TSR being a quarterly publication), the 'alternative' system had essentially become the standard system. This issue also presented an initiative system, which was the simple "roll 1d6 for each combatant and add dexterity bonus; re-roll each round". This system has changed often over the course of D&D's lifespan, so we'll be returning to it many times in this series.

There is also an extensive combat example given in that FAQ, which we will return to in the next column, when we fully dive into OD&D, starting with looking at the original game's classes!

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References:

Gygax, Gary and Arneson, David, Dungeons & Dragons. 1st edition, Tactical Studies Rules, 1974.
Gygax, Gary and Perren, Jeff, Chainmail, 3rd edition, Tactical Studies Rules, 1975.

Towards a History of RPG Mechanics - Part One: Chainmail

If you've ever played tabletop RPGs at all, you probably have some familiarity with D&D. Indeed, the tropes it codified have spread into computer games and become part of the cultural zeitgeist of fantasy in general, so that even those who have never played a tabletop RPG at all often know the basic concepts of character classes, levels, wizards who don't wear armor, healing priests, and so forth.

However, D&D itself evolved very quickly in its early years. And so, the purpose of this installment of the Towards a History of RPG Mechanics series is to go over Chainmail, the precursor to D&D, in some detail.

Chainmail began as a brief set of miniatures rules for playing medieval battles, written by Jeff Perren early in 1970. He introduced them to the Lake Geneva Tactical Studies Association, of which Gary Gygax was a leading figure. Gygax revised them, publishing the expanded version as the "Geneva Medieval Rules" in the wargaming magazine Panzerfaust. A few months later, with the rules expanded still further, they were published again in the Domesday Book, the newsletter of the Castle & Crusade Society.

There were very few medieval miniature wargames available at the time, and Gygax & Perren's rules generated considerable interest, resulting in further expansions for them being submitted to Domesday Book. By the end of the year (still 1970!), Gygax was developing the rules into a game to be called Chainmail for Guidon Games. The first edition was published in March of 1971, and became Guidon Games' biggest seller... and included in it was 14 pages on how to add wizards, heroes, dragons, and other fantasy elements to your medieval battles: the "Fantasy Supplement", which would inspire Dave Arneson to create the Blackmoor campaign which would spawn D&D.

From a mechanical standpoint, Chainmail had four systems, three of which interacted with each other:

1. The original core game - a mass-combat miniatures game with a 20:1 or 10:1 figure scale (i.e., one figure representing 10 or 20 people on the battlefield). This occupied most of the rules, and included rules for melee, missile weapons, siege weapons (catapults, bombards, cannon), morale, terrain, weather, and sieges. Basic resolution was through rolling six-sided dice for the attacking figures: a 6 on a die always resulted in a kill, 5-6 sometimes did, and 4-6 did in a few instances. Mounted troops sometimes got to roll multiple dice. The basic concepts of this system are quite similar to modern miniatures games; while it's vastly simpler than, say, Warhammer, a Warhammer player reading the rules would be nodding along at a lot of what's in them.
2. The Man-to-Man combat system - used for 1:1 scale combat. This was intended for smaller battles and small actions within a siege - for example, a group of elite troops attempting to steal into a castle and open the main gates. Each figure was assigned an individual weapon and armor, and the chance to kill an opponent was determined by cross-referencing your figure's weapon vs. their armor on a table, then rolling two six-sided dice (2d6) against the difficulty shown there. This also had a subsystem for missile combat at the individual level. It's this system that Dungeons & Dragons recommended using for combat.
3. A "Fantasy Combat Table" (also referred to in the rules as the "Fantastic Combat Table"), which was used for "heroes", "super heroes", "wizards", and various monster types (e.g., dragons, elementals, giants, trolls) when fighting against each other. This worked similarly to the Man-to-Man system, but with the character types being used on attack and defense instead of weapons and armor, and with the addition that a roll exactly equaling the number required was a "push back" instead of a kill. These character types also were given equivalencies to various numbers of figures in the core game, with modifications - for example, the rules for an Air Elemental say that it attacks as four Light Horse, is impervious to normal attacks, and adds two to its dice roll against airborne opponents. These equivalencies were used when interacting with 'normal' units.
4. A jousting system, which was really something of a "bonus minigame". The complete jousting system would fit on a single page quite easily, and it was very much a rock-paper-scissors sort of game, with no dice used. Instead, the two players each chose their aiming point and defensive stance (for example, one might aim for the opponent's helm and defend with shield high, while the other chose to aim at the base of their opponent's shield and lean right). These choices were cross-referenced on a table, which gave the results. This was supposed to be done as part of a tournament scenario, where knights would ride against each other three times or until one (or both - simultaneous 'kills' could happen) were unhorsed. A point system was presented as well, counting points for such things as breaking lances, having your helm knocked off, and injuring an opponent, as well as for unhorsing. Thus, players could play multiple knights against each other, or form 'teams'.

The jousting system had no means of interacting with the other three - indeed, the rules specified that it was only to be used for "friendly" tournament combat. (Which makes a good deal of sense - tournament lances had special, blunted tips instead of spear-type tips, making it much easier to unhorse a foe without killing them.)

The Man-to-Man combat system shows an increase in detail - and also shows Gygax's fascination with authentic medieval weaponry and armor, which will crop up again in D&D and AD&D. With the different interacting systems, we also see Gygax's fondness for unique subsystems to handle different aspects of the game, which will also continue forward.

With the Wizards of Chainmail, several of the spells that became D&D standards appear: fireball (here still 'fire ball', lightning bolt, phantasmal forces, and others). Oddly, Clerics make no appearance in Chainmail.

We also see in Chainmail something else that will be typical of Gygax's output for D&D and AD&D... namely, badly organized rules. For example, in the version I have (3rd edition, published by TSR, after they'd acquired the game from Guidon Games), the "Trolls (and Ogres)" entry states that what are commonly called Trolls are actually Ogres, and that True Trolls are much more dangerous. It then proceeds to give the rolls needed for various fantasy types to kill a True Troll. However, the Fantasy Combat Table only gives a single entry for Trolls and Ogres, meaning that someone playing the game needs to remember that the distinction exists, and to go look up the True Troll in the text instead of using the table when one is involved in combat. For additional fun, the entry says that True Trolls "fight as Giants on the Fantasy Combat Table"... but this is apparently merely supposed to mean that they attack as giants, since their listed defenses against various opponents in the text are different from those of Giants.

Another major source of unclearness is how the different subsystems interact. For example, the Man-to-Man and Mass Combat systems use completely different methods for determining initiative... but you may have both sorts of combat happening on the same battlefield. For another, the fatigue system says that a fatigued troop should "attack at the next lower value (heavy foot = light foot)". But what's the "next lower value" for, say, a troll when fighting a treant?

None of this is a serious obstacle, of course, and gamers can and did work out their own ways of handling such obscure points. However, this does become a problem when dealing with tournaments and such, which we'll talk about more when we get to discussing AD&D.

Next time, we'll dig into the Man-to-Man rules of Chainmail a bit more, and start into D&D itself!

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References:

Appelcline, Shannon, Designers & Dragons: the 70s. 2nd edition, Evil Hat Productions, 2015.
Gygax, Gary and Arneson, David, Dungeons & Dragons. 1st edition, Tactical Studies Rules, 1974.
Gygax, Gary and Perren, Jeff, Chainmail, 3rd edition, Tactical Studies Rules, 1975.
Schick, Lawrence, Heroic Worlds, 1st edition, Prometheus Books, 1990.