The evolutionary dynamics of the three strategies of T and θ in the public good game. Filled cycles in S₃ denote stable equilibria and open cycles denote unstable equilibria. All orbits in the system converge to stable state which is a coexisting state of C-players and D-players. For given T values, the fraction of C-players in the stable state on the C–D edge increases as θ increases. Moreover, for given θ values the fraction of C-players decreases as T increases. Other parameter values are N = 20, θ = 1 , k = 0.8, c = 1, c 1 = 0.2 , and δ = 0.3 respectively.