In role-playing games, the types of magic-users are more delineated and are named so that the players and game masters can know which rules apply.[1]:385 Gary Gygax and Dave Arneson introduced the term "magic-user" in the original Dungeons & Dragons as a generic term for a practitioner of magic (in order to avoid the connotations of terms such as wizard or warlock); this lasted until the second edition of Advanced Dungeons & Dragons, where it was replaced with mage (later to become wizard). The exact rules vary from game to game.[citation needed] The wizard or mage, as a character class, is distinguished by the ability to cast certain kinds of magic but being weak in combat; subclasses are distinguished by strengths in some areas of magic and weakness in others.[15] Sorcerers are distinguished from wizards as having an innate gift with magic, as well as having mystical or magical ancestry.[16] Warlocks are distinguished from wizards as creating forbidden "pacts" with powerful creatures to harness their innate magical gifts.