We know that Tit-for-Tat and variants do very well in iterated-Prisoner's-Dilemma tournaments. However, such tournaments are a bit unrealistic in that they give the agents instant and complete information about each other's actions. What if this signal is obscured? Suppose, for example, that if I press "Cooperate", there is a small chance that my action is reported to you as "Defect", presumably causing you to retaliate; and conversely, if I press "Defect" there is a chance that you see "Cooperate", thus letting me get away with cheating. Does this affect the optimal strategy? Does the probability of getting wrong information matter? What if it is asymmetric, ie P(observe C | actual D) != P(Observe D | actual C)?