Figure 2. Performance of the conditional cooperators in the presence of noise.

An asterisk after a move indicates that this move was caused by an error. When the conditional cooperators are playing against a copy of themselves, Forgiver performs very well as it can recover from an accidental defection within three rounds. Against defection-heavy strategies like Grim and ALLD, Forgiver gets exploited in each second round. Both TFT and WSLS are not error correcting as they are unable to recover back to cooperation after an unintentional mistake. Only another mistake can enable them to return to cooperative behavior. When Grim plays against itself and a single defection occurs, it moves to the defection state with no possibility of returning to cooperation.