Arrows of harming (or healing for undead mobs) do not stack with bow damage, what ever damage source does more damage overrides the other damage source.
If the harming effect does more damage then the bow would with normal arrows then only the damage from the harming effect is applied.
If the bow damage with normal arrows is more damage then the harming effect then only the bow damage is applied.
This is determined before damage reduction, so a power V bow fully drawn and using an arrow of harming (instant damage II) against a target in diamond armor (just for example) will only do about 2 hearts of damage. If instead the bow is hardly drawn at all then it will do 6 hearts of damage, the damage from the instant damage II effect.
Demonstration: https://youtu.be/9OW9YXTFnTo
Steps to reproduce:
/give @s crossbow/give @s minecraft:tipped_arrow{Potion:"minecraft:strong_harming"} 32/summon minecraft:blaze ~ ~ ~ {Health:16,NoAI:1b}Shoot the blaze with the crossbow
/data get entity @e[type=blaze,limit=1,sort=nearest] Health
Expected behavior: The blaze would have died, having taken 7-11 damage from the arrow plus 12 from the instant damage effect for a total of 19-23 damage.
Observed behavior: The blaze survives with 4 health; the arrow damage was disregarded.
Reason: see MC-111626.
Linked issues
is duplicated by 17
MC-278617
A bow with power and an arrow of harming takes the same amount of health as a bow without enchant.
Resolved
MC-265397
An arrow with instant damage effect doesn't deal more damage
Resolved
MC-237761
Arrows of Harming/Healing vs Armored Foes
Resolved
MC-133584
Tipped Arrow of Harming acting strangely
Resolved
MC-140807
Instant Damage arrows not working in 1.13.2
Resolved
relates to 2
Comments 21
Note that the Combat Test Snapshot V5 fixes this issue by making projectiles grant 0 invulnerability frames. If this feature is introduced in a major release snapshot, we'll have the fix.
Affects 23w33a. Here are some repro steps:
Steps to reproduce:
/give @s crossbow/give @s minecraft:tipped_arrow{Potion:"minecraft:strong_harming"} 32/summon minecraft:blaze ~ ~ ~ {Health:16,NoAI:1b}Shoot the blaze with the crossbow
/data get entity @e[type=blaze,limit=1,sort=nearest] Health
Expected behavior: The blaze would have died, having taken 7-11 damage from the arrow plus 12 from the instant damage effect for a total of 19-23 damage.
Observed behavior: The blaze survives with 4 health; the arrow damage was disregarded.
The game is not choosing between the arrow and the potion damage. Instead it is not applying the potion damage or is only applying it partwise because the mob or player is still on damage cooldown from the arrow damage, see MC-111626.