How does a radius effect deal with obstructions? Does the radius expand and simply affect every non blocked square? Does it go through walls? Does it go around corners?
Like the Cleric's Channel Energy for example. I just don't see how this works if there is anything other than a big open area.
Best Answer
A lot of this is from Aiming a Spell, but, in short, you should determine if the effect's a burst, spread or emanation; then determine the effect's shape (e.g. cone, cylinder, line, sphere); then mark up the battlefield. That's because
Most Areas of Effect Stop at Obstructions...
The key word is most. An area of effect--like a burst or an emanation--stops when it hits things:
...But There Are Exceptions
Spreads don't stop at obstructions. Instead a spread
Also, cylinders don't stop at obstructions. Instead a cylinder has a
Emphasis, in all cases, mine.