Fig. 2.

The exponent $\mathit{\gamma }$ for the mean fixation time [Eq. (28)] plotted against the density of zealots $m$ for the prisoner’s dilemma game with $a=1$, $b=0$, $c=1.2$, and $d=0$ (solid line) and the snowdrift game with $a=\mathit{\beta }-0.5$, $b=\mathit{\beta }$, $c=\mathit{\beta }-1$, $d=0$, with $\mathit{\beta }=1.5$ (dotted line). We calculated $\mathit{\gamma }$ on the basis of Eqs. (26), (27), and (55)