Is the damage of a higher-level Monk's unarmed strike reduced by the Heavy Armor Master feat?

Question

At 6th level, Monks get the Ki-Empowered Strikes feature which states (emphasis mine):

Starting at 6th level, your unarmed strikes count as magical for the purpose of overcoming resistance and immunity to nonmagical attacks and damage.

Meanwhile, the Heavy Armor Master feat states (emphasis mine):

[...] While you are wearing heavy armor, bludgeoning, piercing, and slashing damage that you take from nonmagical attacks is reduced by 3.

How do these features interact, especially given that Ki-Empowered Strikes are not actually magical? Would Ki-Empowered Strikes count as magical to ignore the damage reduction of Heavy Armor Master, or can they only count as magical specifically for resistance and immunity?

Answer 1

Technically speaking, "damage [...] is reduced by 3" is neither Resistance nor Immunity, so it doesn't get overcome by a monk's fists.

That said, player-side effects like these don't often come into contact. It's certainly possible for two PCs to get into a fight where this matters, most often due to confusion, domination, etc., but ending up with this particular pair of abilities in conflict is the edgiest of edge cases. Monsters almost always use basic Resistance for this purpose. While I can't guarantee there's no enemy or spell anywhere that gives nonstandard damage reduction, I haven't seen it.

Because of that, as a DM, I can't see any balance issues with taking a broader reading that monk unarmed strikes just count as magic weapons any time it matters to an attack. I would not get too hung up on the exact text. It's never fun to tell your players "no, that doesn't work", especially when they seem at first glance to have a class ability that's specifically made for the situation at hand.

Normally, restrictive rules can be traced to one of two sources: a restriction to enforce game balance (such as, say, the rule about only being able to cast a cantrip at the same times as a bonus action spell), or a restriction to enforce the flavor of a specific ability (such as sneak attack being limited to small, quick weapons). Since this doesn't appear to do either, I'm left to wonder why it would be written this way. I suspect this is one of those situations where "helper text" accidentally made the ability more limited than it was meant to be. If the monk's ability simply said "the monk's fists count as magic weapons", that could immediately make your player ask "What does that mean? Why do I care?" (or worse, start thinking their unarmed strikes are innate +1 weapons), so I think they put in text that clarifies the benefit that magic unarmed strikes bring -- and it covers 98% of situations, but incidentally excludes a couple of weird corner cases that it maybe shouldn't.

Answer 2

Heavy Armor Master gives neither resistance nor immunity to nonmagical attacks. Ki-Empowered Strikes therefore has no interaction with Heavy Armor Master.

Answer 3

You've emphasised the wrong part of the explanation of the Ki-Empowered Strikes feat. The explanation clearly states the 6th (or greater) leveled monk's fists "count as magical (weapons)". It is unequivocal, therefore that the resistance to nonmagical weapons granted by the Heavy Armour Master feat is nullified by the Monk's Ki-Empowered Strike.

To elaborate (as some are confused by my answer judging by the comments below) "resistance to" something in the rules is generally the case where a die roll is required to determine whether full or half damage is taken. When viewed in the context of physical (weapon) attacks however, which is what the OP is about, it would seem nonsensical - laborious and clumsy - to consider a gaming session where the GM has to roll a die for every physical attack made to determine whether full or half damage is taken. That would go against the essence of ADnD being a game and therefore being a vehicle for enjoyment.

This being the case, it is sensible to interpret the words "resistance to" in this instance only as being synonymous to "reduction". It simplifies the action, allows the game to flow without unnecessary interruption and increases enjoyment.