The children’s game rock-paper-scissors has a simple yet elegant structure: rock beats scissors; scissors beats paper; paper beats rock. Of the three possible moves, each defeats one, only to be defeated by the other. It’s almost karmic. Indeed, it’s a kind of equilibrium that scientists now say may govern conflict throughout the universe.

At least among lizards. In an article in last month’s issue of The American Naturalist, a team of biologists described the curious mating strategies that they observed in a species of European lizard. Some of the male lizards (call their type “rock”) use force, invading the territory of fellow males to mate with females. Others (“paper”) favor deception, waiting until females are unguarded and sneaking in. Still others (“scissors”) work by cooperation, joining together to protect one another’s females.

The three types of lizard, which the scientists monitored over several years in the French Pyrenees, are locked in a cyclical sort of standoff. For a time, the deceivers flourish at the expense of the intruders, who are too busy marauding to pay attention. Then the cooperators win out over the deceivers, who can’t slink past the guards. And then the intruders vanquish the cooperators, whose openness exposes them to aggression. Then the cycle repeats. It takes about four years.

Barry Sinervo, the lead author of the paper and a biologist at the University of California, Santa Cruz, has seen all this before. In the ’90s, he came across the same four-year cycle of mating strategies in a genetically distant species of North American lizard. Even the behavior of the North American lizards was not a complete surprise: in 1982, the evolutionary game-theorist John Maynard Smith predicted, using mathematical models of conflict, that such arrangements would be found in nature.