Centaurs are the half-horse, half-human hybrids of Greek myth for which, it has been observed, no one has yet come up with a definitive way to design trousers. Which to me clearly indicates that they don’t wear any. Don’t come to me with your hang-ups, man.
In the Harry Potter series, centaurs are standoffish, territorial and even a bit malicious, but in Dungeons and Dragons, as far back as I can remember, they’ve been labeled good creatures—although I’m pretty sure they were originally chaotic good rather than neutral good, which makes more sense to me. Anyway, the upshot is, centaurs are unlikely to attack unprovoked and may prefer to try to subdue and capture their enemies rather than kill them. Doesn’t mean they can’t give you a good hoof-clout, though.
With a single-peak ability contour—exceptional Strength, but merely above-average Dexterity and Constitution—centaurs are also another sort of hybrid, between a brute and a shock attacker. As I use the terms, shock attackers hit fast and hard, then get out, because they’re not cut out for prolonged melee engagement; brutes engage and tank it out until their enemies are dead. With centaurs, we’re maybe looking at something in between: a creature that engages for just two or three rounds, then disengages.
The Charge feature gives centaurs a good boost on that initial shock attack, adding 3d6 piercing damage when they move 30 feet in a straight line toward their targets just before attacking. Note also that the centaurs’ pikes give them 10 feet of reach, which gives them the ability to strafe and maybe sidestep that whole brute–vs.–shock attacker question by not coming within their opponents’ melee reach in the first place.
However, the centaur’s movement speed is only 50 feet. At least 30 feet of the centaur’s movement will be consumed by the initial charge, leaving it no more than 20 to move away. That means that on its next turn, it has to use at least 10 feet of its movement to move away before turning around and Charging again. After that second Charge, it’s in melee and staying put.
Plus, the centaur’s hoof attack is a couple of points better than its pike attack, the reach of that is only 5 feet, and the centaur’s melee Multiattack comprises one pike attack and one hoof attack, never two pike attacks. So I think the conclusion we come to is that even though the centaur can strafe without incurring an opportunity attack, it probably won’t. Instead, its initial attack will be to charge from a distance of 35 to 50 feet, strike with its pike for the extra Charge damage, then follow up with its hooves for maximum first-round damage and remain engaged in melee for a round or two.
The next question is at what point the centaur withdraws from melee. Let’s say that as long as the centaur is unhurt or only lightly wounded, it keeps fighting toe-to-toe. But once its enemy has managed to moderately wound it (reduce it to 31 hp or fewer), it makes one final Multiattack, then moves away at its full speed. This risks incurring an opportunity attack, but the centaur’s nowhere near death’s door yet, and it’s willing to eat that one attack knowing that it can easily outpace nearly any humanoid opponent.
Centaurs making ranged weapon attacks with their longbows do so from a distance of 45 to 50 feet, and they actively try to flank and encircle their enemies. However, the centaur’s longbow attack is objectively inferior to its melee attacks, in terms of both hit probability and damage. Plus, you can’t attack to subdue with a ranged weapon, only with a melee weapon. So we have to think about why the centaur is fighting. If it’s defending its territory against an aggressive invader, it’s not going to be overly concerned with whether it kills the invader or not. And it’s rare that player characters will be fighting against centaurs unless either (a) the PCs are evil-aligned and are aggressive invaders; (b) the PCs are trespassing on the centaurs’ territory, but without aggressive intent; or (c) it’s all just a crazy misunderstanding.
In cases (b) and (c), the centaurs are better off not using their bows at all, because of the risk of accidental murder. But also, if the PCs really are nonhostile, somebody should pipe up and offer parley before the centaurs are wounded badly enough to make them back off, and also before any PC is knocked unconscious. In case (a), on the other hand, figure that one out of every four centaurs is an archer that’s going to provide long-range fire support for its melee-engaged comrades, and that if one of those comrades has to retreat due to injury, the archer centaur will charge in to relieve it, while the injured centaur will assume the former archer’s role.
When a majority of a group of centaurs are seriously injured (reduced to 18 hp or fewer), they’ll call a retreat. Any uninjured or only lightly injured centaurs will act as a rearguard for a round while the more injured ones Disengage and run away. Then they’ll Dash off to join them.
Next: rot grubs.