There are mathematical solutions to search and evasion, many of them: games in which the area is divided into a grid and players move one, two, three squares at a time. The hunted may move first or second or not at all—sometimes concealment and inaction are the better postures. It depends on whether you award your seeker with senses or whether they must move blindly, either at random or by playing the odds. Patterns emerge—whorls of probability and intersection.