The fight-or-flight response is a typical physiological reaction to an imminent threat, which prepares the body to fight or flee. Such a mechanism can be also exploited to some extent in game design to elicit strong emotions in players. However, in first person shooters, fleeing is often a not viable option, making fight inevitable. In this work, we suggest that map design can be effectively used to deal with this issue. In particular, we presented a procedural content generation approach, based on evolutionary computation, to evolve maps for Cube 2, an open source first person shooter. Our results show that the design of evolved maps is effectively able to foster the emergence of a fleeing behavior, even in AI controlled characters specifically designed to fight and chase the opponents.