Sneaking cloaks your character in an environmental object that allows them to move unseen by NPCs, however if you move into their red sight cones they will notice you and engage battle or pull you out of stealth. Increasing your sneaking skill makes NPC sight cones smaller. If you intend to steal an object you should always be in stealth so that you can tell when an NPC can see you or may see you, it also grants you bonus damage in combat if you attack from stealth. The talent Guerrilla increases attack from sneak damage by 25%.