XFX
XCX
XFX
A medium creature is flanked on his north and south side by two other medium creatures.
If he then has Enlarge Person cast upon him, what happens? I know that the environment being too small simply means he would either burst it or stop growing, but what about if he simply doesn't have 2x2 free squares around him due to other characters?
If one of the characters flanking him was his ally, would that change anything?
I've generally ruled it as "Adjacent creatures are pushed into adjacent squares, where permitted. Allies are moved instead of enemies, if possible. Enemies are moved if no space can be opened up otherwise. Characters being moved get to choose which adjacent square they end up in."
I'm not aware of any more official ruling on it.
You're casting a 1-round-cast spell (or drinking a 50g potion). The slight advantage of getting to move an ally's probably fine. :P
Also: If you're in such tight quarters where bumping people around is an issue, it's probably not the best position to be casting enlarge person in, anyway.
I'd probably rule that other Medium creatures are shoved as well BUT... devil's advocate...
"If insufficient room is available for the desired growth, the creature attains the maximum possible size and may make a Strength check (using its increased Strength) to burst any enclosures in the process. If it fails, it is constrained without harm by the materials enclosing it--the spell cannot be used to crush a creature by increasing its size."
RAW suggests that you'd have to perhaps make opposed Strength checks, and if you fail, you'd gain the squeezing condition.