 When the number of states of the world, the number of signals, and the number of actions increase from 2, the situation rapidly becomes much more complex. If there are \(N\) states of the world, \(N\) signals, and \(N\) actions, the total number of possible strategies equals \(N^{2N}\). For \(N=2\), this means there are 16 possible strategies, as we have seen. For \(N=3\), there are 729 possible strategies, and a signalling problem where \(N=4\) has 65,536 possible strategies. Given this, one might think that it would prove difficult for evolution to settle upon an optimal signalling system.