Resistances and Magical Weapons

[DontEatRawHagis]

So I was looking at the Flame Skull and noticed it didn't say Resist Non-Magical weapons, but instead piercing it lead me to two questions.
1. Do magical weapons ignore resistances?
2. If a monster is resistant to Non-magical weapons and slashing does a magic sword ignore both resistances?

[RickAllison]

So I was looking at the Flame Skull and noticed it didn't say Resist Non-Magical weapons, but instead piercing it lead me to two questions.
1. Do magical weapons ignore resistances?
2. If a monster is resistant to Non-magical weapons and slashing does a magic sword ignore both resistances?

1) They ignore resistance to non-magical weapon attacks only

2) It ignores the first, but is resisted by the second.

A flameskull resists magical arrows as well as it does non-magical ones or piercing damage from any source.

A treant would resist any bludgeoning or piercing damage. Dripping Meteor Swarm on a bunch of them would mean the fire damage is doubled, but the bludgeoning damage is halved.

[Ninja_Prawn]

So I was looking at the Flame Skull and noticed it didn't say Resist Non-Magical weapons, but instead piercing it lead me to two questions.
1. Do magical weapons ignore resistances?
2. If a monster is resistant to Non-magical weapons and slashing does a magic sword ignore both resistances?

1. No. The flameskull resists all piercing damage, even from magical weapons.
2. No. The magic hammer works as normal, but the magic sword is resisted.

A more illustrative example is swarms. Imagine swinging a sword at a swarm of bees. Every bee it hits will die, but that has little impact on the swarm as a whole, hence resistance to slashing damage. A magical sword can't do any more damage to an individual bee, and it can't hit any more of them than a mundane sword can, so the resistance is not overcome by a magical weapon.