Describes a winning strategy in the development of cooperation. The first step is to be cooperative (nice). The second step is to do what is done to you. If the other side is nice, be nice again. If the other side is uncooperative, then be uncooperative. Basically, after the first step, do what the other side does. It is important, however, to distinguish between an opponent who is claiming to be nice (to deceive you) and one who is actually being nice. 4-02