Term for the phenomenon when an undesirable but competitive strategy dominates
A game outcome that is Pareto optimal or Pareto efficient is one where no one player can be made better off without making at least one player worse off. So a Nash equilibrium can easily be Pareto sub-optimal (or Pareto inefficient), which means that it is possible to one player can be made better off without making at least one player worse off. However, "The interesting thing about the prisoner’s dilemma is that all options are Pareto optimal except for the unique equilibrium, which is for both to defect."