Everyone who took sixth-grade social studies knows the story of the minotaur—literally, the Bull of King Minos, that inhabited the labyrinth into which the tyrant threw his prisoners. In the myth, the minotaur (there was only one) was the cursed offspring of a bull and Minos’s wife, Pasiphae (ew), and the labyrinth was built by Daidalos to contain it so that it didn’t rampage among the populace, devouring the king’s subjects. In Dungeons and Dragons, minotaurs (plural) are a humanoid species with bovine heads and hooves.
So . . . evolved creature or not? The Monster Manual flavor text seems to want to have it both ways:
Minotaurs are the dark descendants of humanoids transformed by the rituals of cults . . . [who] come to the cult seeking a life free from authority’s chains—and are liberated of their humanity instead as [the demon lord] Baphomet transforms them into the minotaurs that echo his own savage form. Although they begin as creations of the Horned King, minotaurs can breed true with one another, giving rise to an independent race of Baphomet’s savage children in the world.
If the MM can’t commit to one explanation or the other, maybe we can’t, either. Maybe we have to accept that some minotaurs are evolved beings, and some aren’t. Maybe the logical extension of this premise is that some minotaurs behave as an evolved creature would, while others don’t, depending on whether they’re born as minotaurs or transformed by a curse. In other words, if your adventure includes a minotaur, in order to know how it will behave, you need to give it a backstory.
A minotaur is a high-Strength, high-Constitution brute, and a stupid one at that. If it’s a transformed minotaur we’re talking about, it might be interesting to consider its low Intelligence as a possible source of resentment—surely it wasn’t that stupid before it was transformed, and maybe it has memories of what it used to be like to know and understand things.
In contrast to its Intelligence, its Wisdom is very high. The designers probably gave it this ability simply to make it hard to sneak up on (it has proficiency in Perception as well, with a +7 skill modifier), but we have to consider what else this score implies, especially in combination with its pitiable Intelligence.
A creature with Intelligence of 7 or less operates purely from instinct. That doesn’t mean it uses its features ineffectively, only that it has one preferred modus operandi and isn’t going to be able to adjust if it stops working. On the other hand, an evolved creature with Wisdom of 14 or higher chooses its battles carefully and fights only when it’s sure it will win (or will be killed if it doesn’t fight). So not only does a minotaur perceive the world around it keenly, it’s also good at basic threat assessment, though not to the extent of being able to identify its enemies’ particular weaknesses. Will it parley if it recognizes that it’s outmatched? Probably not: judging by its below-average Charisma and its lack of proficiency in any social skill, talking isn’t really its style. But it will keep its distance, glaring menacingly.
That being said, a transformed minotaur probably won’t have the same self-preservation drive that a natural-born minotaur will. It may sense that it’s outmatched yet attack an enemy or group of enemies anyway, simply out of hatefulness, hoping to cause its foes as much pain as possible before they release it from its own miserable existence. Natural-born minotaurs, on the other hand, know no other existence and will be keen to keep their lives going as long as possible.
Minotaurs have darkvision, so they’re subterranean and/or nocturnal—you won’t find them roaming around outside in broad daylight. They also have Labyrinthine Recall, a fluffy, silly nod to the Minos myth which doesn’t have any impact on their combat tactics. The real meat of their tactics is in their other two features, Charge and Reckless.
Reckless is the same as the barbarian class feature Reckless Attack: it gives the minotaur advantage on all attack rolls while giving its opponents advantage on their own attacks against it. The wording of the feature makes it clear that it’s strictly optional.
I’ve looked at two other creatures with this feature before, the barlgura and the berserker. In the case of berserkers, reckless fury is so essential to their nature that there’s no reason for them not to use this feature all the time. Similarly, the barlgura is a demon, a fiendish being of chaos and malice, for which Recklessness is apt in any and every situation.
But again, we come around to the question of whether the minotaur is transformed or natural-born. I think a transformed minotaur is more likely to be Reckless—it has nothing to lose. A natural-born minotaur, on the other hand, has more respect for its own skin. Consider that, having darkvision, minotaurs will prefer to fight in the dark. Against blinded enemies, they attack with advantage already, so adding Reckless onto the pile doesn’t help them. Meanwhile, those blinded enemies attack with disadvantage, which adding Reckless would negate, actually hurting them. So while they possess barely a flicker of cognitive activity, they do at least have the horse sense (bull sense?) not to use Reckless against opponents who are already blinded by darkness. Instead, natural-born minotaurs attack Recklessly only when they have no other advantage against their opponents, especially if their opponents already have advantage on attacks against them anyway.
Finally, Charge, which minotaurs use to initiate combat. Although their base movement speed is 40 feet, their Charge requires them to move only 10 before attacking, and it can push their targets up to 10 feet away, setting up Charge after Charge. (Head golf!) This is the core of the minotaur’s attack sequence, which isn’t complicated. On its first round, it attacks a target with Charge, most likely the nearest one. Charge nearly doubles the damage of a gore Attack action and requires the target to make a Strength saving throw or be thrown up to 10 feet back and knocked prone. If the target doesn’t get back up, or if it gets up but then moves away, the minotaur will repeat its Charge until the target is obliterated. If, on the other hand, the target gets up and moves toward the minotaur, or another enemy engages it in melee, it will switch to a simple Attack action with its greataxe.
With their bestial Intelligence, minotaurs have no heuristic for target selection. Whatever’s closest, they headbutt or chop at, and they keep headbutting and chopping until their enemies don’t get back up or they themselves don’t. Transformed minotaurs, in all likelihood, will fight to the death. Natural-born minotaurs may decide, upon being seriously injured (reduced to 30 hp or fewer), that they’d rather live to fight another day. Not being smart or disciplined enough to Disengage or deft enough to Dodge, they Dash away when they flee.