Helpless

A PC or NPC is helpless when it is asleep, held, mesmerized, prone or has its strength reduced to zero. No action can be taken, objects cannot be interacted with (not even rest shrines or chests), and inventory items cannot be moved, traded, equiped or consumed.

Often this is caused by a spell such as Hold Person or Sleep.

All attacks against a helpless opponent are critical hits (although they may be treated as normal hits in the case of fortification).