Monday, January 31, 2011

Basic D&D: On Cavalry

As I said here, "Cavalry... get surprisingly short shrift in the classic D&D rules. The three-page Chainmail section on man-to-man combat (p. 25-27) manages to contain more detail on mounted combat than the entirety of the OD&D and AD&D system, for example." Let's look a little deeper at the issues around cavalry.

Quotes to Consider

First, recall that the primary thesis around cavalry is this: Cavalry attack is intrinsic to the unit's own movement. Before saying anything else on the matter as regards D&D, I'll look at a few quotes from Matthew Bennett's excellent essay, "La R├ęgle du Temple as a Military Manual, or, How to Deliver a Cavalry Charge". (Accessible in full online here; highly recommended.) Bennett relates the regimented formation of the Knights Templar immediately prior to their engagement on the battlefield, from their official manual of conduct:
When the knights were armed they took up their position in line, placing their squires with their lances and shields before them. They were expressly forbidden to break ranks or charge without permission, and even turning their horses' heads to the rear in order to fight, or in response to an alarm, was not allowed (161)... With permission he could take his lance and shield...
Then he quotes a very evocative passage from George Bernard Shaw's "Arms and the Man", describing a cavalry charge:
You can tell the young ones by their wildness and their slashing. The old ones come bunched up under number one guard; they know they're mere projectiles, and that it's no use trying to fight. The wounds are mostly broken knees from horses coming together.
And finally a supporting quote from Louis Edward Nolan (of "Charge of the Light Brigade" fame):
A charge, even on good ground, is seldom executed by the whole line at once; the enemy is reached in succession by different points in the line more advanced than others. It is therefore of the greatest consequence that those detachments which reach the enemy first shall be compact, and go at him as one man, to burst through.
I think the Shaw quote is perhaps the most poignant: They know they're mere projectiles. In this sense (thinking of archetypal European "heavy cavalry" in the Middle Ages) the men are actually rather unimportant. Their role is to hold the lance with discipline; in this sense they are simply proto-cannon, delivering a massive shock across the battlefield when called upon. The expectation is for the initial charge to "burst through", or else it is something of a disappointment.

Rules from Chainmail

That said, let's now think about cavalry as it appears in D&D. As mentioned above, the Chainmail man-to-man rules have more detail than later D&D publications. In particular, Chainmail features on page 25-27:
  1. "For non-mounted versus mounted men: add one to the die roll of the mounted man, subtract one from the die roll of the man on foot - 1st round only horsemen add two."
  2. "On the 2nd round of melee the horse as well as its rider attack, the horse counting as the following weapon(s), and able to attack a different opponent than its rider, but only footmen: Light 1 Mace; Medium 2 Maces; Heavy 2 Flails"
  3. "Men may be unhorsed by footmen if they specifically state this is their intent before dice are rolled. A score equal to a kill, with no subtraction for their being afoot, indicates a successful unhorsing. An unhorsed man is possibly stunned: Die Score 1-2 Not stunned; 3-5 Stunned 1 turn; 6 Stunned 3 turns. Remounting requires one-half turn, as does voluntary dismounting."
  4. Jousting as a complete and separate system from the rest of the rules: "Each player selects an aiming point (his attack) and a position in the saddle (his defense)... The aiming point of each player is matched against the position of their opponent and the result found. Results can vary from both opponents missing to both being unhorsed, as a study of the jousting Matrix will reveal. (See Appendix C.)..."
So that's Chainmail, with its fairly comprehensive rules for mounted combat. Almost none of this material is included in the OD&D or AD&D core rulebooks. Some additional questions we might have to rule on in this context -- (1) Should the modifier for mounted-vs-foot be doubled if we use it in the context of D&D (current sidebar poll would say "yes")? (2) Is the penalty for attacking mounted men a matter of cover or height (for example, can footmen with long polearms, or giant-types, ignore this modifier)? (3) Do archers suffer the same penalty to shoot cavalry? (4) If a footman's attack misses because of the mounted modifier, does it hit the horse accidentally? (5) Can men opt to intentionally attack the mount instead of the rider? (6) Can unhorsing be accomplished with any weapon type, or even open-handed?

On Lance Double Damage

Interestingly, in the 1E AD&D PHB, all of the "situational combat modifiers" are scrunched into footnotes in the table of weapon types (p. 37-38). I would argue that (as compared to Chainmail), this is a fairly deficient presentation method. Here we see:
  1. Certain types given the ability to "set" for double damage defensively, against a charge (military fork, glaive, glaive-guisarme, javelin, spear).
  2. Certain polearms having reserved the ability to dismount a rider with a normal "to hit" roll (fauchard, fauchard-fork, military fork, glaive-guisarme, guisarme, guisarme-voulge, lucern hammer, ranseur).
  3. Certain types capable of disarming an opponent with hit on AC 8 (ranseur, spetum).
  4. Missile attack adjustments of 0/-2/-5 for short/ medium/ long ranges.
  5. Any weapon striking +2 against the back or unseen; +4 against stunned, prone, motionless opponents.
  6. Lances doing "twice indicated damage against creatures of any size when it is employed by an attacker riding a charging mount."
These tidbits seem new to AD&D, and are not seen even in the "Alternative Combat System" additions and changes of Sup-I (Greyhawk, which otherwise introduces variable weapon damage and weapon-vs-AC modifiers, p. 13-15) -- although the famous details on polearms can first be seen in an article in the TSR magazine.

This last detail (lance weapons doing double damage in a charge) was "sticky" in the sense that it became the archetypal rule for dealing with the increased shock of a cavalry charge; it was propagated forward into all later versions of D&D (2E, 3E, B/X, etc.) But does it truly make sense?

I would argue "not really". The true impact of the cavalry charge comes simply from the speed, strength, and inertia of the horse. The fact that in D&D it's the rider that gets to use their attack level, Strength modifier to hit and damage, and weapon adjustment is frankly missing the point. There's nothing special about the lance in this regard (other than the length allowing the blow to be delivered before most counters). If there were, then one might ask what the point is with charging with implements such as bayonets or swords, as was commonly done in other contexts (see sidebar photo; Leicestershire PAO Yeomanry c1930).

On Mounts Attacking

The one notable constant throughout classic D&D is that mounts get no attack in the first round of contact, but do get one or more attacks in subsequent rounds:
  • "On the 2nd round of melee the horse as well as its rider attack..." [Chainmail, p. 25, repeated from above]
  • "When mounted troops are engaged in combat the mounts will not count in the first melee round. On the second and succeeding rounds of melee, however, mounts will fight as follows..." [Swords & Spells, p. 18]
  • "Warhorses fight on the second and succeeding rounds of melee, as long as their rider remains mounted. Their attack consists of two hoof thrusts and a bite." [AD&D Monster Manual, p. 53]
There is a major problem with this -- It makes cavalry more damaging in a non-charging situation! In broad terms, the charge grants two units of attack (one lance for double damage); while the sustained melee grants three or even four units of attack per turn (granted that as of Sup-I horses are given 2-3 attacks; and at a higher attack level from hit dice, to boot). To be more specific, assume an AD&D 1st-level fighter with lance and longsword on a heavy horse versus an AC 5 opponent. Then in the charge round we expect 4.8 points of damage (8/20 to-hit x 6 lance damage x 2 doubling); but in sustained melee we expect 6.85 points per round (man 6/20 to-hit x 4.5 longsword + horse 10/20 to-hit x (4.5+4.5+2)). That's a +42% damage improvement by virtue of not charging! And that just ain't right.

This artifact is a combination of (a) the only benefit of the charging being the double lance damage (and relatively minor +2 to-hit bonus), and (b) the very large number of attacks per round given to horses after D&D Sup-I, but only in non-charging rounds.

On the Move/Attack Sequence

In short, D&D mechanics pretty uniformly adjudicate movement in its entirety, prior to any melee attack resolution. (See Chainmail p. 9, Swords & Spells p. 3, 1E AD&D DMG p. 66, etc.) The problem with this move-strike-end-turn sequence is that it overlooks the "overrun" effect of cavalry breaking and stomping directly through a line of defense. As Louis Edward Nolan would agree, a cavalry charge that does not "burst through" the enemy is a failure, and this is in fact impossible in the standard D&D turn sequence.

So ideally, we would like a mechanic wherein the cavalry lancer drops his target and then keeps moving. (There is a rule like this in the Chainmail mass rules, p. 15; and also a rule that makes standing mass cavalry weaker, p. 17; but such rules appear nowhere in either the man-to-man section nor any flavor of D&D rulebook.) Other questions then arise from the gap: Can footmen be knocked over without being killed? Can the horses get some kind of trampling or bludgeoning attack as they run by? And so forth.

On Barding

Another amusing complication is that while every version of classic D&D features barding (horse armor) on its equipment list, none specify what the effect is. OD&D has just one type of barding (Vol-1, p. 14), while AD&D has three types (leather/chain/plate, PHB p. 36), none of which have any commentary in the rules (recall horses have different starting AC than men; AC 7).

If we look back to the Chainmail man-to-man melee table, then we have at least a clue (Chainmail p. 41); the last two columns in the weapon-vs-armor chart are for "Horse: No Armor/ Barded", and in each case the barded score is 2 pips more difficult than the unarmored (single exception: morning star scores are identical, likely a typo?). If that's the intent for D&D, then we again have to consider if we should convert this as a +2 AC or +4 AC bonus.

On 3E Figure Positioning

A special note here on the 3E miniature-based rules: "A horse takes up a 5-foot-by-10-foot space, and you take up a space 5 feet across. For simplicity, assume that you occupy the back part of the horse." [3E PHB p. 138].

While initially attractive (each of two spaces has one "head" in it), on further reflection this doesn't work so well. To begin with, a two-square-long lance now barely reaches ahead of the horse, seemingly losing any advantage for first-attack-from-reach. More keenly, an enemy directly in front of the horse cannot exchange sword blows with the rider at all! (The rider & footmen each have one square reach, but the horse's head keeps a 2-square gap between them; again see sidebar sword-wielding cavalry above to see how this makes no sense.) So if the rider figure cannot be positioned directly in the middle of the horse (where they really sit), then I would argue in this case that the rider is more properly positioned in the front square of the horse (perhaps mostly leaning forward).

Some Suggested Fixes

So granted how terribly deficient the D&D rules are for mounted combat (the norm being exactly the opposite of what would be reasonable!) we come to a point where we wonder how much alteration and divergence we have the stomach to import to our game.

First, we might consider the usual desired doubling of modifiers from Chainmail. We could make mounted men -2 to be hit by footmen; +2 to hit footmen; and +4 to hit in the initial charging round (original source Chainmail p. 25). Same for barding: Give it a +4 bonus to horse AC (AC7 becomes AC3, as plate)?

We might momentarily consider possible game-theoretic advantages of different levels of mounted armor bonuses; say we use the Chainmail rule for felling a rider and possibly stunning them (above). Then when is it advantageous to attack the rider directly (lower HD, but likely better armor and mounted penalty to-hit) versus the mount (more HD, but possibly lower AC and being able to stun the rider and take away the mounted bonus), assuming that's permitted?

According to the computer simulations that I've run, if the rider AC bonus is +2 then it is always the best choice to attack the rider (even assuming unbarded horses); if the bonus is +4, then it's better to attack light riders and heavy horses; if the bonus is +6, then it's always best to attack the horse. However, in the latter two cases we would actually be making plate-armored riders totally unhittable (to-hit 21 or more for OD&D fighters up to 3rd level), which is probably not what we want. In my game I've decided to use the +2 bonus for rider AC.

Secondly, we might reconsider the mechanics for mounts moving and attacking. In my game, I strongly recommend giving horses only a single attack per round, which seems both reasonable as they simultaneously carry the rider and maneuver, and also prevents the prolonged melee from outweighing the effect of the charge round (i.e., sticking with by-the-book OD&D, and also Swords & Spells p. 18). In addition, we might consider a charge-round sequence such as the following: (1) mount & rider move to lance range, delivering initial attack; (2) mount continues move to first target or one behind it, delivering one hoof/trample/smashing attack; (3) mount & rider continue balance of movement if way is clear.

This doubles the shock potential on the charge round (granted both knight & horse make attacks), and offers the hope of cavalry "bursting through" on the attack, at the expense of some added mechanical burden on our play. However, in practice I've found that even this actually makes very little difference; the chances for 1st-level attack success in D&D are fairly low (less than 50% to hit, even with charge bonus; and even then no guarantee to score killing damage), so we have at best a faint chance to drop at most 2 men in file. Thus the difference is fairly marginal, if we do not add some additional large creative bonuses for the charge attack.

Open Questions

I end with a compiled list of questions we could ask about mounted combat in classic D&D:
  1. Should the modifier for mounted-vs-foot be doubled (+1 to +2) if we use it in the context of D&D?
  2. Can any of the following ignore the rider AC bonus: (a) footmen with polearms, (b) archers, (c) giants?
  3. If a footman's attack misses because of the mounted modifier, does it hit the horse?
  4. Can men opt to intentionally attack the horse instead of the rider (and is there any symmetric modifier or chance to hit the rider)?
  5. Can unhorsing be accomplished with any weapon type in OD&D?
  6. Should there be some radical change to how charge attack to-hits are adjudicated (i.e., no lance exceptionalism, use horse attack level, speed indicator, re: to-hit and damage)?
  7. How many attacks per round should horses be given?
  8. Should horses continue to be barred from any attack in the charge round?
  9. Should there be an "overrun" capacity in which cavalry can move/attack/move (and possibly more) within a single charge round?
  10. What level of AC should barded horses be given?
  11. Should riders be positioned at the front or rear of the horse (i.e., can they sword-attack an enemy in front of the horse)?
  12. Do we use the "rider stun" chart from Chainmail? What if the horse is dropped in a non-intentional-unseating attack?
  13. Do warhorses attack on their own if the rider is killed or unhorsed? Do they run from the line of battle, or stand motionless?
  14. Should we use a +4 to-hit bonus for charging cavalry (doubled from Chainmail's cavalry-first-turn-bonus, p. 25), and a separate +2 bonus for anyone else charging (as per AD&D DMG p. 66)?

Friday, January 28, 2011

D&D a Threat to U.S. Prisons

Should I be glad that D&D is still sufficiently subversive in some circles that the 7th Circuit Court of Appeals upheld its being prohibited from prisons as being a security threat? Or angry that our judicial system is mentally stuck someplace in the last century? Opening line of ruling from Judge Tinder:
After concluding that the popular role-playing game Dungeons and Dragons (“D&D”) represented a threat to prison security, officials at Wisconsin’s Waupun Correctional Institution took action to eradicate D&D within the prison’s walls.
Primary argument is that team-based play "mimics the organization of a gang", and that the presence of DM/referees may result in "D&D players looking to Dungeon Masters, rather than to the prison’s own carefully constructed hierarchy of authority, for guidance and dispute resolution." Official judgment at More comment at GeeksAreSexy.

To answer my own question: Guess I swing more "angry" on this most days.

Monday, January 10, 2011

Basic D&D: Chainmail Conversions

OD&D is, of course, based heavily on the Chainmail Fantasy miniatures game. In fact, it is included as recommended equipment (Vol-1, p. 5; in the same category as dice and OD&D itself) and it is incorporated by reference at numerous points (e.g., Vol-2, p. 5: "Special Ability functions are generally as indicated in CHAINMAIL where not contradictory to the information stated hereinafter...").

You probably know that Chainmail's man-to-man and fantasy combat mechanics functioned by way of 2d6 rolls, whereas OD&D's "Alternative Combat System" functions by way of the ubiquitous d20. Therefore, as is obvious to pretty much anyone who's looked at it, the modifiers that appear in Chainmail would have very different effects probability-wise, if used verbatim within the core D&D system.

Intuitively speaking, a conversion from Chainmail to OD&D should more-or-less double any modifiers, in that Chainmail's 2d6 roll has a range of about 10 (11, really) and OD&D has a range of 20. But in addition to that, Chainmail's non-uniform distribution varies from point to point. Look at the table above for specifics: depending on where the initial target for success was, a +1 bonus in Chainmail might be the equivalent of anywhere from 1/2-point to over 3 points in D&D. On average, however, a +1 Chainmail bonus is worth +1.82 D&D bonus (i.e., 20/11; but easily rounded up to +2, as expected).

Nevertheless, the real issue I want to highlight is this: Throughout the entire publication history of OD&D, AD&D, d20 System, etc., the precedent was established to translate Chainmail-defined bonuses on a direct 1-for-1 basis (i.e., entirely overlooking this issue). Here are some examples:
  • Goblins, kobolds, and orcs. Per Chainmail, "When fighting in full daylight or bright light they must subtract 1 from their Morale Rating, as well as 1 from any die rolled" [CM p. 29-30]; in OD&D, this translates to an identical, "when they are subjected to full daylight they subtract -1 from their attack and morale dice." [Vol-2, p. 7]. Likewise, this same modifier is carried forward into later editions [AD&D MM p. 47, et. al.]
  • Weapon-vs-armor. Taking a single sample row from the weapon-vs-armor types in Chainmail, we see target numbers for a hand-axe of "7/7/8/9/10/10/11/12" [CM p. 41]; in the Greyhawk D&D supplement we see hand-axe modifiers of "+1/+1/0/0/-1/-1/-2/-3" [Sup-I, p. 13]. This is fundamentally the same progression, converting CM targets of 8 or 9 to +0, and any pips above/below that on a 1-for-1 basis. In fact, this is true for the entire OD&D weapon-vs-AC table, which is then copied forward to AD&D with only minor adjustments (for example, the hand axe modifiers are identical except for a single pip difference at AC4). [AD&D PHB p. 38].
  • Missile fire. In the Chainmail man-to-man missile fire table, a target progression of -2/-1/0 is shown for each range category of short/medium/long [CM p. 41], and this coverts 1-for-1 to the D&D to-hit rule of +2/+1/0 [Vol-1, p. 20]. However, in AD&D this was wisely altered to become 0/-2/-5 [AD&D PHB p. 38].
  • Mounted combat. Per Chainmail, "When fighting men afoot mounted men add +1 to their dice for melees and the men afoot must subtract -1 from their melee dice" [CM p. 26]. While this rule wasn't transcribed into the OD&D or AD&D core books themselves, it is copied unchanged into places such as the 1E AD&D Wilderness Survival Guide [WSG, p. 86], 2E AD&D [DMG, "Mounted Combat"], and 3E D&D [3E PHB, p. 138].
  • Parrying. For lighter weapons, Chainmail provides the ability to parry, "subtracting 2 from the attacker's roll" [CM p. 25-26]; this is copied without change into Holmes Basic D&D: "The parry subtracts 2 from the attacker's die roll" [Holmes D&D p. 21].
  • Magic swords. In Chainmail fantastic combat, "they give a plus 1 to the dice score... Excaliber [sic] and other 'Super Swords' would give a plus two or three!"; and in OD&D we also see magic swords from +1 to +3 in value [Vol-2, p. 23]. That said, in AD&D swords were expanded from +1 to +5 in value [DMG p. 124], and Arthur's sword was in fact later given the maximum +5 bonus [AD&D DDG, p. 18].
So, if you aim to use OD&D by itself, and include by reference the details on man-to-man combat that appear only in Chainmail (such as several bullet-points above), then you've got a somewhat uncomfortable dilemma to resolve. You need to either (a) use the modifiers as written (1-for-1), and thus greatly minimize the originally-designed probability effects, or (b) convert the modifiers (2-for-1), and thus violate the by-the-book rules in OD&D, AD&D, et. al., on each of these issues (and more generally, the overall precedent for such translations).

What would I want to do? Personally, I think I prefer option (b). I'm willing to chalk up these 1-for-1 translations as fundamentally an oversight and a "mistake" in D&D, and consider a more faithful conversion in probability on a 2-for-1 basis. In addition, I might make the philosophical case that no 1-point situational modifier is worth the mental effort to track. For example, if someone has a +1 Strength bonus to all melee attacks (such that it can be included on the PC card), then by all means, use that. If a weapon-vs-AC effect, or a special skill or ability, gave +2 in a given situation, then that is worth tracking. But tracking fiddly +1 sometimes-modifiers makes a difference so rarely, that it's better to entirely avoid. (3E "Bard Song": I'm looking at you and your ilk.)

In fact, this overall philosophy matches those modifiers that were freshly introduced at the time of AD&D. Cover modifiers are given in increments of at least +2 (cover AC +2/4/7/10; DMG p. 64). The bonus for charging is set at +2 (DMG p. 66). Special to-hit bonuses are in increments of +2 (opponent off-balance +2; opponent stunned or slowed +4; DMG p. 67). Likewise, if I have a shortcut system that generates results within 1 pip of the official tables (such as Target 20: see sidebar), then in my games I'm happy to call that "close enough". In short, I might argue: Situational modifiers in D&D should be at least +/-2 to be worth bothering with. And this is synchronous, I think, with the desire to double Chainmail modifiers if we opt to use them within D&D.

What's your preference? Poll results here.

Wednesday, January 5, 2011

New Year's Book of War

So I'm scrambling a bit to square up some very basic fortification rules, and the setup to properly playtest them a few times. New Year's Day I put the finishing touches on a model and sat to down to run an assault on a, um, certain castle situated on a high bluff overlooking a river. (I'll also be running this scenario at the RECESS convention in New York on the evening of Sunday Jan-16 -- ironically in the same place as the martial arts class where I got the black eye that I'm currently sporting. But I'll tell everyone it was my previous players. Ha! Anyway, see for more info.)

As Moltke the Elder would tell you, your understanding of any scenario changes immediately upon contact with the players. On setup and explanation my girlfriend asked, "Do I get a princess in the castle?" And I had to reply, "Geez, I don't think there are any women in the entire complex -- except maybe a serving wench in the tavern." That started things off super-well with the feminist opposition. (Gygaxians may make whatever they wish from the foregoing).

Turn 1 -- Situation: Monsters have poured out of the nearby woods in the dark of night, surrounding the castle and attempting to scale the bluff face before a full alarm can be raised. Of course, underworld monsters can see at night, but men defending the castle have to carry torches, and can only light up to the base of a wall where someone is stationed (otherwise location is known only vaguely by sound; archery, for example, is effectively impossible). Defenders are in red, mostly men in chainmail with crossbows, polearms, and a small number of heavy men-at-arms in plate. I'm controlling the monsters in blue, including a bunch of light goblins, medium orcs, hobgoblins with crossbows, and a squad of hill giants. I've already shot a number of the defenders off the walls. (As usual, each figure represents 10 of the given creature type in a certain space.)

Turn 2 -- General chaos. As monsters get to the top of the bluff (a task of significant difficulty in itself), they pull up ladders and attempt to escalade over the wall.

Turn 4 -- Attrition. This is a tough task for my monsters. None have gotten inside yet; one unit of orcs has already been routed off the table.

Turn 6 -- Giants (after hitting some of my own guys with thrown stones) decide to clamber up the bluff and start over the wall. A force of 60 men await them in the inner bailey.

Turn 7 -- This was a real crappy turn for me. It started out well with a larger-than-usual number of monsters getting up the bluff to the base of the wall. Unfortunately, a series of excellent rolls by the opposition killed them all, and then all but one of the attached units routed. Neither did the giants get over the wall (instead taking hits from defenders now on the rampart).

Turn 9 -- Last of the orc attackers flee into the night.

Turn 10 -- Final defeat. 'Twas the serving wench that killed the beast?

Monday, January 3, 2011

Basic D&D: Close Combat Trinity

I'd like to spend some time thinking about the basics of D&D, which is to say, the most fundamental assumptions built into the combat mechanics of classic/original D&D. (This is not to be confused with the B/X style "Red Box" rulesets, which ironically I was just commenting on at another blog a few minutes ago.)

Obviously D&D evolved out of medieval miniatures wargaming (Chainmail). If we boil premodern land combat down to its most basic level, then I would argue that we find three fundamentally atomic types of hand-to-hand combatants (leaving out missile troops for the moment), which I'll call: Swords, Cavalry, and Pikes.

You'll see these three core types in the diagram above. The arrows indicate dominance (which type defeats which other type). In the broadest possible terms, you could track a history in which the ancient Greek phalanx (pikes) was superseded by the flexibility of Roman legionnaires (swords), which were ultimately replaced by medieval European cavalry, which was ultimately bested by Swiss pikes, which began losing battles to Spanish swordsmen in the 16th century (reverse around the graphic), etc.

When I say "Swords" here, I'm ultimately thinking of any shield-and-something combination where you walk up to an opponent and swing a melee weapon in an arc with your arm in order to strike a blow (which could include swords, axes, flails, etc.) Cavalry are charging lancers. Pikes are any long, pointy weapon that you can stick out defensively. Perhaps you could think of this categorization as the "Rider/Pike/Sword" triad (i.e., RPS, so as to emphasize the analogy with rock/ paper/ scissors).

Consider the core D&D combat sequence of movement, followed by an attack (or some other permutation; the important thing is that they're discrete steps within a turn of action). Interestingly, each of the three core combat types interacts with the move/attack sequence in a different way.

Swords (or any handheld weapon that delivers a blow by stroke) work the most elegantly within this system, and they're also the type most emphasized by D&D itself. It does make sense that moving up to an opponent by leg power, and then standing and swinging a weapon with your arms several times, are indeed separate and distinct components of an action. It also makes sense that this type of action takes the spotlight in D&D, with its focus on close combat within the confines of a dungeon, where other longer weapon types are impractical.

As much as it pains me to say it, cavalry and pikes very intrinsically work counter to a separately phased move/attack sequence. The essence of a Cavalry attack is that it happens while in motion -- the horses gallop, the lances held straight ahead and still, the moment of impact, and if successful, the breaking of the enemy line and continuation of the gallop. The attack is fundamentally one with the attacker's motion. Pikes are the inverse of that; primarily the advantage is defensive, again with the pole weapon held out straight ahead and still, but set so as to take advantage of the enemy's movement, as the foe's momentum causes them to be impaled upon the presented points. In other words, the ideal attack is fundamentally one with the opposition's motion. In both of these cases, I would argue, the discrete move/attack sequence breaks down, because it is inherently antithetical to the nature of the attack; the impact is due solely to the forward momentum itself.

Cavalry and pikes, meanwhile, get surprisingly short shrift in the classic D&D rules. The three-page Chainmail section on man-to-man combat (p. 25-27) manages to contain more detail on mounted combat than the entirety of the OD&D and AD&D system, for example. Again, this is not entirely surprising, but notable nonetheless. If you do want to run games with prominent usage of classic cavalry and pike units, then you've got to make certain independent adjudications (filling gaps) about how they work. That's just the nature of the beast, because it wasn't part of D&D's core competency.

In summary:
  1. Historically: Swords beat Pikes beat Cavalry beat Swords.
  2. Sword attack is a separate impulse from movement.
  3. Cavalry attack is intrinsic to the unit's own movement.
  4. Pike attack is intrinsic to the unit's enemy's movement.
  5. Cavalry & pike are only cursorily treated in dungeon-centric D&D.
Hopefully I can continue some of this thought process on a semi-regular basis. Happy New Year!