George and Martha stumble home from a faculty party at the university where George teaches. Right away we get the sense that they're not the happiest couple in the world – in fact they seem to be rather bitter. Martha informs her husband that a young couple, Nick and Honey, are coming over for a few after party drinks. The doorbell chimes and the scene is set for alcohol, agony, and some serious emotional devastation.
George and Martha spend most of the first act viciously attacking each other. George pokes at Martha about her age and alcoholism; he also spends a good amount of time trying to humiliate and outwit Nick, a young up-and-coming professor by whom George feels threatened. Also, sprinkled throughout the act are hints about George and Martha's mysterious son, who for some as yet unknown reason is not a subject either one of them is particularly comfortable talking about.
For the most part, Act 1 belongs to Martha, who uses the time to systematically torture her husband. She does this by blatantly flirting with Nick in front of George and continually providing her guests the intimate details of George's failures. The most painful of these is the fact that George has never advanced to be the head of the History Department, despite the fact that Martha's father is the president of the university. George becomes so enraged when his wife reveals this that he shatters a liquor bottle on the bar. All this tension is too much for Honey, who ends the act by running out of the room to vomit (she's had a bit too much to drink).
Act 2 begins with a little male bonding. Though Nick and George, have a lot of animosity towards each other they still see fit to share some of the intimate details of their lives. Nick talks about how he married Honey because he thought she was pregnant. It turned out that it was all a hysterical pregnancy and was just in her mind. George tells Nick a story about a drunken night out with some his school friends, one of whom had in his past accidentally killed both of his parents. Martha returns with Honey and it's not long before the craziness begins again.
Before you know it, Martha and Nick are dancing all slow and sexy right in front of both of their spouses. Martha decides to heap some more humiliation onto George and brings up his novel, another big failure. It turns out the book was autobiographical and was about a boy who accidentally killed both his parents. Apparently, George was talking about himself in the story he told Nick earlier. Martha continues the story, saying that her father wouldn't let George publish the novel and he burned it in the fireplace. George becomes even more enraged than before and tries to strangle Martha to death.
George decides it's time to play a new game, which he calls "Get the Guests." He reveals that Nick told him about Honey's hysterical pregnancy. Honey is appalled and once more leaves the room to vomit. Martha and Nick, both determined to get back at George, begin to make out right in front of him. He pretends he doesn't care. At the end of the act, Martha leaves George alone in the room, declaring that she's going upstairs have sex with Nick.
By the beginning of Act 3, things have really changed between Nick and Martha. Apparently, Nick was unable to perform once he got upstairs with Martha. Now she treats him like trash. George returns with a bouquet of snapdragons and declares that it's time to play one last game – "bringing up baby." He forces Martha to begin talking about their son. After we hear the son's life story, George announces that a telegram came while Martha and Nick were in the bedroom. Their son is dead.
Martha totally freaks out and tells George that he's not allowed to kill their son. It becomes apparent that George and Martha made up their son. He's another game, an illusion that the two of them made up to bring some comfort to their desolate lives. Quietly, Nick and Honey take their leave. In the end, George and Martha are left alone with no more illusions.