The Elements are the integral substances which form our world. They consists entirely of the same type of atoms and are not compounds. Generally used in role-playing games and most often in strictly fantasy-based ones, though there are sometimes allusions to the classical elements in other genres. Commonly used as the basis for spells and set in opposing/balancing pairs such as Fire-Water, Earth-Wind. There are other element systems, such as the Chinese Wu Xing five elements of Fire, Metal, Earth, Wood, Water. Another variant uses the four familiar from the Hellenic system and adds Light and Dark, or Void and Aether/Ether.
The four-element system deriving from Hellenic Greece is the most common, consisting of Earth, Water, Air and Fire.