Ok I have a 64x32 base icon and i've been told that since Byond isnt 100% functional with this system that the top half of the base wil be unrecognized by mobs and such and will be passed through. Now i do not want projectiles flying through a persons head without them taking damage, but i also don't want to half to split everything into a bottom and top because i've seen games do that and what happens is that the top half doesnt always appear. If you have a coding solution or just some advice i would love to hear it.
Just check if the location of the projectile is one y above the the multi-tiled mob.
In response to Ulterior Motives
SO its possible for it too still work? We just have to make sure the projectile hits the top part is that what your saying?
In response to Fantasie Productions
As the projectile moves check it's location. Check to see if a mob is in the location, or the location directly below it. Then call your damage procs, or whatever.