Focus of Interaction
The Focus of Interaction (FoI) theory is an attempt to classify live action roleplaying games and to help determine what is and is not a live action roleplaying game.
The FoI theory divides LARP along two axises.
Interaction Axis
The horizontal axis is the Interaction axis. To the left, we have larps that are classified as Adventure Style.
An adventure style LARP bears the most superficial resemblance to a tabletop roleplaying game. The focus of interactions of an adventure style LARP is player to environment. The players’ characters tend to be a party of adventuring heroes, and while the characters may have individual differences, they band together and fight alongside each other. The world, in this case, can be portrayed by non-player characters (portrayed by people who are not players, often called non-player characters (NPCs), monsters, or cast), GMs, elaborate props, scenery, or signs.
Players in adventure style LARPs tend to find their characters trying to solve puzzles, fight monsters, deal with powerful foes and generally live the lives of heroes.
To the right, we have Theater-Style larps.
The focus of interaction in a theater style LARP is player to player. The player characters are not a solidified party, but rather a group of factions or even each player out for him or her self.
Theater style LARPs usually focus on politics, negotiations, power struggles, and social interactions. GMs are still needed when the players wish to do something that affects the world outside of the player set (for example, making a phone call to an ally not in the game, or exploring a nearby haunted house). Cast players are fewer and there are usually fewer adventurish plots. The heroes and villains (if any) are all portrayed by players, not by cast or GMs.
This isn't to say that larps must be strictly adventure style or theater style. Most larps fall somewhere along the axis, having combinations of those elements.
The Focus of Interaction (FoI) theory is also used to help determine if something is or is not a live action roleplaying game. The theory defines two other foci of interaction.
If the FoI is player to GM, then the event is classified as a tabletop roleplaying game. Again, there can be crossovers and most tabletop rpgs tend to have a good deal of player-to-player interactions. However, if interactions with the GM are what is needed to move the event along, then that is the focus of interactions.
If the FoI is player to audience, then the event is classified as improvisational theatre. In improvisational theatre, the participants tend to work together to produce a dramatically satisfying story for the audience. Live action roleplaying games tend not to have an audience. Again, some experimental events, especially Eclectic Theater Style events have tried to produce a hybrid of LARP and improv theater.