FUNDAMENTALS OF GAME DESIGN, SECOND EDITION
Dominant Strategies in PvE Games
As Chapter 9 explained, most games offer a large number of different types of challenges but a somewhat smaller number of actions with which to overcome them. One action may overcome several different types of challenges. This encourages players to experiment to find the right action or combination of actions to surmount each type of challenge, whereas only offering one unique action for each type of challenge makes for a dull game.
Implementing fewer actions does introduce a potential problem, however. By creating actions that can overcome several different kinds of challenges, you risk accidentally creating exploits, actions so powerful because of a weakness in the design that the player becomes unstoppable. This occasionally happens
when players use an action in a way that you did not expect. For example, in an old side-scrolling space-shooter game on the Super Nintendo Entertainment System (which this book does not name to avoid embarrassing the individuals responsible), the player could, after upgrading her weapons to a certain level, make her way through the rest of the game without ever losing a life by traveling as low on the screen as possible and keeping her finger on the fire button. Although clearly unintended, this position made her invulnerable to enemy attacks.
No one has yet invented a way to prevent these problems other than through playtesting, trying as many actions and as many combinations as possible on each challenge. The smaller the number of actions that you implement in your game, the less likely you are to introduce a dominant strategy by accident because you will be able to test them all rigorously. Be especially careful with powerups and special actions that give the player more power than usual; these require extra testing.