Storytelling game
A storytelling game is a game where two or more persons collaborate on telling a spontaneous story. Usually, each player takes care of one or more characters in the developing story. Some games in the tradition of role-playing games require one participant to take the roles of the various supporting characters, as well as introducing non-character forces (for example, a flood), but other systems dispense with this figure and distribute this function among all players.
Since this person usually sets the ground and setting for the story, he or she is often referred to as the "storyteller" (often contracted to "ST") or "narrator". Any number of other alternate forms may be used, many of which are variations on the term "gamemaster"; these variants are especially common in storytelling games derived from or similar to role-playing games.
Role-playing games
The most popular modern storytelling games originated as a sub-genre of role-playing games, where the game rules and statistics are heavily de-emphasised in favor of creating a believable story and immersive experience for all involved. So while in a conventional game the announcement that one's character is going to leap over a seven-meters-wide canyon will be greeted with the request to roll a number of dice, a player in a storytelling game who wishes to have a character perform a similar feat will have to convince the others (especially the storyteller) why it is both probable and keeping within the established traits of their character to successfully do so. As such, these games are a subclass of diceless role-playing games.
Not all players find the storytelling style of role-playing satisfying. Many role-playing gamers are more comfortable in a system that gives them less freedom, but where they do not need to police themselves; others find it easier to enjoy a system where a more concrete framework of rules is already present. These three types of player are discussed by the GNS theory.
Some role-playing game systems which describe themselves as "storytelling games" nevertheless use randomisers rather than story in the arbitration of the rules, often in the form of a contest of Rock, Paper, Scissors or a card drawn from a deck of cards. Such "storytelling" games are instead simplified or streamlined forms of traditional role-playing games. Conversely, most modern role-playing games encourage gamemasters to ignore their gaming systems if it makes for a more enjoyable story, even though they may not describe themselves as "storytelling" games.