Can I use Catapult to hurt an Archmage who is in his Antimagic Field?
Antimagic Field:
Target: Self
Range 10 feet
Catapult's trajectory is quite unnatural:
The object flies in a straight line up to 90 feet in a direction you choose before falling to the ground
This makes me think that magic does not just fling it, but it is working on it until impact.
However, it could also be just a simplification on the creator's part.
Best Answer
It should be possible, as long as the object you choose is located outside the antimagic field.
Catapult spell is instantaneous, the only magic is used on the object to launch it in chosen direction. It is not concentration sustained as telekinesis. According to the description, the projectile stops if it impacts against a solid surface. It is not a magical effect but pure physical force.
Still, if the caster would be able to cast 8th-leveI abjuration spell, a simple wall of force in a shape of dome, located just outside the antimagic field.
The answer from Wizards of the coast: