A piece of interactive fiction, or IF, is a computer program that generates stories. Exactly what story you will end up reading when you launch an IF program depends on the input you provide. When prompted, you type what you want your character to do in the story. There is no menu of choices, no list of verbs to click. You can type anything you want. The implicit promise is that the program will understand whatever you type, and respond appropriately.
It wont.
Interactive fiction programs understand some fairly complex commands. They also choke on some very basic ones. If you want to avoid frustration, its important to get a feel for the type of input an IF program will be able to process. Thats where this tutorial comes in.