This classic comedy opens in Oscar Madison’s slovenly apartment as a group of his friends is deep into a game of poker. It is no wonder that Oscar is divorced if the condition of his apartment is any indication. The last of the group, Felix Ungar, arrives late and depressed: he and his wife have recently separated and he is trying to hold it together. He is a desperate sort of man, and his friends fear for his mental state. Since Felix has nowhere to go, Oscar invites him to move in with him until he has a chance to figure things out.
At first, Felix’s love of order is the perfect answer to Oscar’s messy house, careless spending, and gambling problems. But soon his fussiness and hypochondriac ways prove extremely annoying to those around him, especially Oscar, who has to decide whether to let his friend stay and drive him crazy or throw him out to retain his sanity. Hilarity ensues as these two very polar-opposite friends have to figure out how to reconcile their differences.