Complex sentence: It was first introduced as a source of wizards' power in a 1969 short story by Larry Niven, in role-playing games by Dungeon Master in 1987 and has since become a common staple in both role-playing and video games.
Split into simpler sentences: It was first introduced as a source of wizards' power in a 1969 short story by Larry Niven, and in role-playing games by "Dungeon Master" in 1987. It has since become a common staple in both role-playing and video games.