# Using and playing different stage games¶

As described in Play Contexts and Generic Prisoner’s Dilemma the default game used for the Prisoner’s Dilemma is given by:

>>> import axelrod as axl
>>> pd = axl.game.Game()
>>> pd
Axelrod game: (R,P,S,T) = (3, 1, 0, 5)
>>> pd.RPST()
(3, 1, 0, 5)


These Game objects are used to score matches, tournaments and Moran processes:

>>> pd.score((axl.Action.C, axl.Action.C))
(3, 3)
>>> pd.score((axl.Action.C, axl.Action.D))
(0, 5)
>>> pd.score((axl.Action.D, axl.Action.C))
(5, 0)
>>> pd.score((axl.Action.D, axl.Action.D))
(1, 1)


It is possible to run a matches, tournaments and Moran processes with a different game. For example here is the game of chicken:

>>> chicken = axl.game.Game(r=0, s=-1, t=1, p=-10)
>>> chicken
Axelrod game: (R,P,S,T) = (0, -10, -1, 1)
>>> chicken.RPST()
(0, -10, -1, 1)


Here is a simple tournament run with this game:

>>> players = [axl.Cooperator(), axl.Defector(), axl.TitForTat()]
>>> tournament = axl.Tournament(players, game=chicken)
>>> results = tournament.play()
>>> results.ranked_names
['Cooperator', 'Defector', 'Tit For Tat']


The default Prisoner’s dilemma has different results:

>>> tournament = axl.Tournament(players)
>>> results = tournament.play()
>>> results.ranked_names
['Defector', 'Tit For Tat', 'Cooperator']