Gee describes the direct speech act as follows: "An umpire in a baseball game says “Strike!” and a “strike” exists in the game. That is what the rules of the game allow to happen. It is a strike if the umpire says it is. Similarly, the rules of marriage allow a marriage to actually happen in the world when a properly ordained minister or a judge says “I now pronounce you man and wife”. Umpires actually make strikes happen and ministers actually make marriages happen. These are what we can call “direct speech acts”. Saying something makes it so, as long as one has said it in the right circumstances (so, “promise” is also a direct speech act, since saying “I promise” in the right settings – e.g., not on a stage as part of play – makes a promise happen)" (p. 31).
References:
Gee, J.P. (2005). An introduction to discourse analysis theory and method. London: Routledge.