Siege weapon vs Swarm

[Darche Schneider]

If you had a catapult and launched the rock at a swarm of fine creatures, does the stone do anything?

Similarly, bolder bullet, being shot at the swarm would it work at all?

[Scott Wilhelm]

I think the answer is the rock would not do anything, but most catapults are made to fire a variety of kinds of ammunition. Some are made to burst into flame. Cannons fire grape shot. I think that stuff should work on a Swarm just fine.

I guess if were a really, really big rock...

[Sandslice]

CRB wrote:

If the check succeeds, the catapult stone hits the square the catapult was aimed at, dealing the indicated damage to any object or character in the square. Characters who succeed on a DC 15 Reflex save take half damage. Once a catapult stone hits a square, subsequent shots hit the same square unless the catapult is reaimed or the wind changes direction or speed.

This suggests that the attack should be considered AoE, and thus the rock deals +50% damage to the swarm. (If you don't agree that it's AoE, consider what happens if a mounted character has his mount standing over an unconscious character, and that's the square that gets hit.)

It's even clearer if you're firing a Trebuchet, which has a secondary AoE zone where half damage is inflicted (or 1/4 on a made Reflex save.)