When two sides remain in battle for long, they co-evolve. This is seen in the natural world in everything from the toughening of grasses vs strengthening of herbivore teeth and stomachs to the changing shape of flowers and bird beaks or insect probosces.
In the man made world we see co-evolution in too many pair situations to count. Here are a few such “games,” each operating on the health of the players in a different way:
Where there is a change that makes an environment suddenly “safer,” people can move toward behavior that would have formerly been risky. This effect — the Peltzman Effect — is said to partially equalize the benefit people receive from greater safety. When personal safety is increased, people take more risks.
But put another way, I think this effect helps us see how much people value safety over other benefits. It is not illogical to choose behaviors that are less safe.