FUNDAMENTALS OF GAME DESIGN, SECOND EDITION
Avoiding Dominant Strategies
A strategy is a plan for playing a game, usually according to a principle or approach that the player believes is likely to produce success. One player may favor an aggressive approach while another may depend on a defensive approach, for instance, but each thinks her strategy has the better chance of bringing victory. The term dominant strategy, which comes from formal game theory, refers to a strategy that reliably produces the best outcome a player may achieve, no matter what her opponent does. Dominant strategies are undesirable because once a player discovers one, she never has any reason to use any other strategy. It makes all other choices pointless and thus limits the fun the player can have with such a game. Still worse is a dominant strategy that one player may use but another player may not, which can occur in asymmetric games (the later section "Balancing Asymmetric Games" discusses this scenario). When that occurs, the dominant strategy not only obviates other strategies, it makes the game unfair. Designing your game's mechanics to avoid a dominant strategy is, therefore, an essential part of game balancing.
Sometimes one single choice can be a dominant strategy, if that one choice gives the player enough of an advantage. This section refers to player strategies, options, and choices interchangeably because any of these may cause one strategy to dominate all others.
Strategies that avoid loss or prevent an opponent from scoring points can also qualify as dominant. Prior to 1955, a basketball team could use endless delaying tactics to kill time on the clock to preserve their lead—a dominant strategy because it prevented the other side from getting control of the ball and scoring. Leagues implemented the shot clock to force the team with possession in such situations to shoot the ball, thus creating more opportunities for their opponents to get it back.
