from otree.api import * c = cu doc = '\nThis is a one-shot "Prisoner\'s Dilemma". Two players are asked separately\nwhether they want to cooperate or defect. Their choices directly determine the\npayoffs.\n' class Constants(BaseConstants): name_in_url = 'prisoner' players_per_group = 2 num_rounds = 1 betray_payoff = cu(300) betrayed_payoff = cu(0) both_cooperate_payoff = cu(200) both_defect_payoff = cu(100) instructions_template = 'prisoner/instructions.html' class Subsession(BaseSubsession): pass def set_payoffs(group): for p in group.get_players(): set_payoff(p) class Group(BaseGroup): pass def other_player(player): group = player.group return player.get_others_in_group()[0] def set_payoff(player): payoff_matrix = dict( Cooperate=dict( Swerve=Constants.both_cooperate_payoff, Continue=Constants.betrayed_payoff ), Defect=dict( Swerve=Constants.betray_payoff, Continue=Constants.both_defect_payoff ), ) player.payoff = payoff_matrix[player.decision][other_player(player).decision] class Player(BasePlayer): decision = models.StringField(choices=[['Cooperate', 'Cooperate'], ['Defect', 'Defect']], doc='This player s decision', widget=widgets.RadioSelect) class Introduction(Page): form_model = 'player' timeout_seconds = 100 class Decision(Page): form_model = 'player' form_fields = ['decision'] class ResultsWaitPage(WaitPage): after_all_players_arrive = set_payoffs class Results(Page): form_model = 'player' @staticmethod def vars_for_template(player): me = player opponent = other_player(me) return dict( my_decision=me.decision, opponent_decision=opponent.decision, same_choice=me.decision == opponent.decision, ) page_sequence = [Introduction, Decision, ResultsWaitPage, Results]