Fight Club is a 1996 novel by Chuck Palahniuk. It follows the experiences of an unnamed protagonist struggling with insomnia. Inspired by his doctor's exasperated remark that insomnia is not suffering, the protagonist finds relief by impersonating a seriously ill person in several support groups. Then he meets a mysterious man named Tyler Durden and establishes an underground fighting club as radical psychotherapy.

After an explosion destroys the narrator's condominium, he asks to stay at Tyler's house. Tyler agrees, but asks for something in return: "I want you to hit me as hard as you can." Both men find that they enjoy the ensuing fistfight. They subsequently move in together and establish a "fight club", drawing numerous men with similar temperaments into bare-knuckle fighting matches, set to the following rules:

You don't talk about fight club.

You don't talk about fight club.

When someone says stop or goes limp, the fight is over.

Only two guys to a fight.

One fight at a time.

They fight without shirts or shoes.

The fights go on as long as they have to.

If this is your first night at fight club, you have to fight.

More Info: en.wikipedia.org