ID:796677
 
(See the best response by LordAndrew.)
Code:
Tutorial_Density
density=1
Entered(atom/movable/A)
if(istype(A,/obj/Blasts/Blast))
return 0
else return 1


Problem description: The blast won't go threw the barrier, whenever it's allowed to.
Best response
It'd be better to use Enter() as that determines whether or not something can step on that turf to begin with. Entered() is moreso for events that occur once you're on the turf.
I figured out the problem. I had the return 0 & return 1 backwards and change it to Enter XD But, also thanks for the new information!