How can one reduce the hit points lost from a Stirge's Blood Drain?

Question

The Stirge is a monster, and it has the Blood Drain action which states (emphasis mine):

Melee Weapon Attack: +5 to hit, reach 5 ft., one creature. Hit: 5 (1d4 + 3) piercing damage, and the stirge attaches to the target. While attached, the stirge doesn't attack. Instead, at the start of each of the stirge's turns, the target loses 5 (1d4 + 3) hit points due to blood loss.

After my character was Blood Drained by a Stirge, I lost the 5 hit points when its turn came back around. One of my allies had the Interception Fighting Style, which can be used to reduce the damage dealt by an attack; however, with the Stirge already latched on, this wouldn't work. And then I got to thinking and realized that I don't know if anything works.

The ability simply says the target loses hit points, with nothing actually classifying it as damage or giving it a type; this leads me to my question: In what ways can someone reduce the hit point reduction from Blood Drain?

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There are things that grant resistance to all damage (or almost all damage), like the Bear Totem Spirit Barbarian or Armor of Invulnerability, but I'm not even sure if the Blood Drain HP loss counts as damage in the first place.

Answer 1

I think you're seeing this the right way: there's no damage dealt, just straight hit point loss with no type at all, and thus not affected by damage resistance (even "all damage" resistance). In the narrative of the game, this isn't your body being pierced or struck or burned; it's straight up blood loss that you can't avoid by, say, wearing armor that resists certain kinds of damage.

Now, that isn't entirely consistent with other similar effects. The obvious point of comparison is a vampire's bite, which deals necrotic damage and also reduces your maximum hit points. Necrotic damage is used in a few other places to represent bleeding or other effects that generally mess with life functions. For example, the Sword of Wounding can 'wound' a creature, dealing the target necrotic damage each turn, which presumably represents blood loss (or something similar for creatures that lack blood), and can be halted with a Medicine check. Abi-Dalzim's horrid wilting, which sucks the water out of living creatures, also deals necrotic damage to its targets.

As written, the stirge's Blood Drain ability doesn't technically deal damage and has no type; but if a DM wanted to treat that as necrotic damage I think they'd be entirely justified in doing so, and it might make the stirge fit into the system a bit better. I don't particularly like the idea of stirges having this quirky mechanic that is shared only by Bearded and Horned Devils and may have weird rules implications by not technically being "damage".

Answer 2

The HP loss via Blood Drain is damage.

The HP loss due to the Blood Drain is indeed damage: this can be confirmed by the following question on the SAC:

If a shadow rolls a critical hit, does it reduce the target’s Strength by 2d4, as well dealing the extra necrotic damage? No. A critical hit lets you roll damage dice twice. An effect that deals damage is one that reduces the target’s hit points. The shadow’s Strength reduction isn’t damage, because it has no effect on the target’s hit points.

A further evidence is in the description of the Horned Devil's Tail attack:

Tail. Melee Weapon Attack: +10 to hit, reach 10 ft., one target. Hit: 10 (1d8 + 6) piercing damage. If the target is a creature other than an undead or a construct, it must succeed on a DC 17 Constitution saving throw or lose 10 (3d6) hit points at the start of each of its turns due to an infernal wound. Each time the devil hits the wounded target with this attack, the damage dealt by the wound increases by 10 (3d6). [...]

We can hence generalize to get the definition of damage:

Damage is HP's loss

Since the Stirge's Blood Drain reduces the HPs of a creature each turn the monster remains attached to the target, the 1d4+3 does count as damage.

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There are several spells that can grant resistance/immunity to all damages.

Some spells provide protection from all kind of damages:

• Warding Bond:

[...] While the target is within 60 feet of you, it gains a +1 bonus to AC and saving throws, and it has resistance to all damage.

• Resilient Sphere: the problem of this spell is that you can not attack.

The sphere is immune to all damage, and a creature or object inside can't be damaged by attacks or effects originating from outside, nor can a creature inside the sphere damage anything outside it.

• Invulnerability:

You are immune to all damage until the spell ends.

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It is reasonable to consider it of piercing type. Resistance/Immunity to piercing damage should work.

It is true that the damage dealt has no explicit type stated, and Darth Pseudonym in their answer provides some reasons for considering this damage of the necrotic type.

I nonetheless would rule that the damage due to blood loss is of the piercing type.

Let's parse again the statistics of the attack (emphasis mine):

Melee Weapon Attack: +5 to hit, reach 5 ft., one creature. Hit: 5 (1d4 + 3) piercing damage, and the stirge attaches to the target. While attached, the stirge doesn't attack. Instead, at the start of each of the stirge's turns, the target loses 5 (1d4 + 3) hit points due to blood loss.

and its further description

Blood Drain. A stirge attacks by landing on a victim, finding a vulnerable spot, and plunging its proboscis into the flesh while using its pincer legs to latch on to the victim. Once the stirge has sated itself, it detaches and flies off to digest its meal.

These two pieces of text tell that the the proboscis is the body part used to deal the initial damage and the subsequent 1d4+3 due to the blood loss. Since the on-hit damage is of the piercing type, it is not unreasonable to consider the following damage of the same type.

Furthermore, this interpretation agrees with the description of the piercing damage (emphasis mine):

Piercing. Puncturing and impaling attacks, including spears and monsters' bites, deal piercing damage.

Answer 3

Kill the flying leeches before they suck your blood.

A stirge can't use its blood drain if it's dead. As such, the best way to prevent this damage is to kill them before they latch onto you. If you're unable to do so, then killing them before their next turn comes up will also prevent this damage.

Answer 4

It does count as damage -- that's pretty much what "losing hit points" means. It is not, however, given a specific damage type; it just says "due to blood loss". Strictly speaking, then, no damage resistances would apply, since those are all based on the type of damage. (Although I could see an argument for the Bear Totem barbarian to resist it, since it resists "all damage except psychic", and the blood drain isn't psychic.)

I would rule, in my world, that it counts as piercing damage, as that's what the initial attack damage type is, and it's a continuation of that same attack, and that makes as much sense as any other choice. Other DMs might rule differently.