Summary

TFDs are used to create models of how the game should work from the player's perspective. By exploring this model the tester can create unanticipated connections and discover unexpected game states. TFDs also incorporate invalid and repetitive inputs to test the game's behavior. TFD tests will demonstrate if expected behavior happens and unexpected behavior doesn't. Complex features can be represented by complex TFDs, but a series of smaller TFDs is preferred. Good TFDs are the result of insight, experience, and creativity.