1. One of the primal forces of the universe in the swords and sorcery fantasy stories by
Michael Moorcock. The most popular of these stories is 'Elric of Melnibone', but there are others which form the a sort of meta-xlogy called the Eternal Champion saga. These stories way be the first contemporary source for the mythical notion of chaos found in
heavy metal music, role playing games,
anime, and computer games.
2. Chaos is one of the 4 primal alignment forces in the Dungeons and Dragons rpg universe, and is the opposite of Law. The other polar forces are Good and Evil. Chaotic creatures value individuality and freedom over discipline, order, society and tradition.