game theory Game theory is the study of mathematical models of strategic interactions among rational agents. Myerson, Roger B. (1991). ''Game Theory: Analysis of Conflict,'' Harvard University Press, p.&nbs1 Chapter-preview links, ppvii–xi It has appli ...

a move by nature is a ''decision'' or ''move'' in an

extensive form game An extensive-form game is a specification of a game in game theory, allowing (as the name suggests) for the explicit representation of a number of key aspects, like the sequencing of players' possible moves, their choices at every decision point, th ...

made by a player who has no strategic interests in the outcome. The effect is to add a player, 'Nature', whose practical role is to act as a

random number generator Random number generation is a process by which, often by means of a random number generator (RNG), a sequence of numbers or symbols that cannot be reasonably predicted better than by random chance is generated. This means that the particular out ...

. For instance, if a game of

Poker Poker is a family of comparing card games in which players wager over which hand is best according to that specific game's rules. It is played worldwide, however in some places the rules may vary. While the earliest known form of the game w ...

requires a

dealer Dealer may refer to: Film and TV * ''Dealers'' (film), a 1989 British film * ''Dealers'' (TV series), a reality television series where five art and antique dealers bid on items * ''The Dealer'' (film), filmed in 2008 and released in 2010 * ...

to choose which cards a player is dealt, the dealer plays the role of the Nature player. Fig. 1 shows a

signaling game In game theory, a signaling game is a simple type of a dynamic Bayesian game.Subsection 8.2.2 in Fudenberg Trole 1991, pp. 326–331 The essence of a signalling game is that one player takes an action, the signal, to convey information to another ...

which begins with a move by nature. Moves by nature are an integral part of games of

incomplete information In economics and game theory, complete information is an economic situation or game in which knowledge about other market participants or players is available to all participants. The utility functions (including risk aversion), payoffs, strategies ...

References

* {{Game theory Game theory