A reliable wireless ad hoc network has to be secured against a selfish behavior. In such a network environment nodes have no incentives to participate actively in packet forwarding. Thus, selfishness is a rational choice for network participants. In this paper we demonstrate how using a strategy based packet forwarding approach can increase throughput in such networks and at the same time can minimize the usage of resources of participating nodes. The strategy defines conditions under which packets are being forwarded. It is based on the notions of trust and activity of the node originating the packet. We demonstrate that selfish behavior becomes unattractive when a certain number of nodes are using this approach. A genetic algorithm (GA) is applied to evolve good strategies, while for evaluation purposes of the strategies a game theoretical model of the ad hoc network is used.