Act one is the beginning, the Genesis of the story. Here the writer must set up what the whole story is about. Act one is analogous to the introduction paragraph of any formal (or informal) essay. The writers job in an essay’s intro paragraph is to set the stage (pun intended) for the rest of the paper. It must state the rules and arguments for the rest of the piece.
This is true with story telling also. If it is a super hero story, the author must inform the audience that the main character (or whoever) has super powers. It is just not believable to have a character breath fire in the resolution to the conflicts brought about in acts one and two unless the writer has given some foreshadowing to the characters abilities.
Furthermore, it makes no sense that a character could win a basketball game in the final seconds of a playoff game, shooting an amazing three pointer from half court, unless the author has hinted that the character has done this before or is at least has picked up a basket ball before.
This may sound stupid but so many stories (particularly) Hollywood movies are guilty of this very crime. Bad stories too often tell the audience that the character is a decent basket ball player (to continue the analogy) but never show that character playing the sport until partway through the movie.
In the set up of the story we must establish the very essence of the characters and world in which they live in. If the “Lord of the Rings” had not shown how much the hobbit loved their holes, the audience would never believe that it was so hard to leave it.
This is not to say that the character can not grow from that point on. On the contrary, the characters should change, but in a believable way. This is true with the environment as well. It makes no sense to create a world in which certain things are not possible only to have characters disregard (or completely obliterate) those rules.
Homework:
Write the first ten pages of a script or story, in which all the rules of the environment and quirks/ attributes of the characters are established. Of course, you can always make changes later to enhance the story. Just remember that this is the time of creation (of the world and the people in it) so you will have to create everything here. Then in Act two you can play around with your creation.
Happy Writing!
