Built into the game are the incentives that drive the game to the equilibrium. Each plays the game doing the best they can no matter what the other play does. This is rather like the chess games in the Queen's Gambit movie. Each player from the position they occupy on the board, looks ahead at the options the opponent will have. Then each player makes the move that is in their own best interest. So why will the entrant enter? Why will the rational incumbent accommodate