A sentient weapon is a common plot device in many works of fantasy, mythology, and science fiction, and is related to the classic motif of the magic sword. Sentient weapons may be human, robotic, or magical, but not all magic weapons are sentient. A sentient weapon may experience a moral conflict from its specific nature as a weapon, or may function as the villain, which, through its intelligence, is able to gain power. Another possibility is that it assists the wielder, or is merely neutral.