Ghast fireballs should deal 6 projectile damage regardless of difficulty level when they hit a mob directly.
Steps to reproduce
Give yourself 2 leather caps.
Enchant one cap with projectile protection.
Give yourself high level health boost and instant health effects so you have lots of hearts.
Make a ghast containment cage of some kind and summon/teleport a ghast inside of it.
Switch to survival.
Let the ghast shoot you while you wear each cap.
Expected result
You take less damage wearing the projectile protection cap when fireballs hit you directly. (Note that if you start to take non-damaging hits, that is a separate bug that can be worked around by changing position slightly between shots: see MCPE-78714) .
Observed result
You take the same damage from direct hits wearing each cap.
Code analysis
The projectile component in fireball.json has no impact_damage section within the on_hit parameter. Compare this to the small_fireball.json, which correctly gives blaze fireballs 5 projectile damage.
Linked issues
discovered while testing 1
relates to 1
testing discovered 1
Comments 1
Bedrock Edition ghast fireballs only deal explosion damage. This is affected by difficulty level and makes ghast fireballs stronger on hard difficulty and weaker on easy difficulty compared to Java. In Java Edition ghast fireballs always deal 6 projectile damage on a direct hit regardless of difficulty. In Java Edition they only deal explosion damage to mobs within the explosion radius of the fireball that are not directly hit, probably because the projectile damage occurs first and then triggers damage immunity. However, in Bedrock Edition explosion damage from a direct hit to the head is about 7.25 on hard and 3.25 on easy. A direct hit lower on the body (e.g. if you tank a shot while walking backwards) can do > 10 damage on normal or hard (relates to MCPE-153770).
This issue is plausibly part of the cause of MCPE-78714. See my the comment on that report.