Ah Tasha’s Hideous Laughter, or simply Hideous Laughter in Pathfinder.
My monster’s fell fast and hard to this spell last night, and though it was a wonderful victory for the PCs, I’m now filled with trepidation at the apparent power of this 2nd level spell.
My first question revolves around the possibilities for the afflicted character/monster, the spell reads [emphasis my own]:
This spell afflicts the subject with uncontrollable laughter. It collapses into gales of manic laughter, falling prone. The subject can take no actions while laughing, but is not considered helpless.
Now, a helpless character means:
A helpless character is paralyzed, held, bound, sleeping, unconscious, or otherwise completely at an opponent’s mercy. A helpless target is treated as having a Dexterity of 0 (–5 modifier).
So, since they aren’t helpless and they can’t take any actions…what exactly can they do once they succumb to Hideous Laughter? — Can they move/stand up? Shift? Take attacks of opportunity? Defend themselves?