The prologue says it all. "Two households both alike in dignity"– the Capulets and the Montagues – are battling it out in the streets of Verona. The play opens with a public brawl. A simple hand-gesture from a Capulet servant to a group of Montague servants spirals into a full-out fight. The Prince arrives to break it up. He's gotten sick of the Montagues and Capulets disturbing the peace, so he decides he's going to lay down the law. From this point onwards, he announces, anyone who fights in public will be put to death. Obviously, this is setting up a big confrontation later in the play. Meanwhile, we're introduced to the two young lovers. On the Capulet side, thirteen-year-old Juliet has just gotten her first proposal. Paris, one of her father's friends and one of Verona's most-eligible bachelors, has asked to marry her. Juliet's never met him, but it seems like a sure thing. On the other side of Verona, Romeo, the only son of Lord and Lady Montague, is supposedly head over heels in love with a girl named Rosaline. Romeo is totally infatuated with her, but Rosaline is not into him. As a result, Romeo is depressed.
Romeo crashes a Capulet party in hopes of seeing Rosaline. Juliet is there dancing with Paris, her maybe-husband-to-be. When Romeo sees Juliet from across the room, he completely forgets about Rosaline. "O, she doth teach the torches to burn bright!" he sighs.
Romeo manages to get Juliet away from Paris, and he compares her to a saint. Juliet likes this, and she really likes Romeo. They have such incredible chemistry that their witty banter turns to kissing in about two minutes. Juliet's nurse interrupts the kissing session. Then comes the bad news: Romeo finds out that Juliet is a Capulet. Then Juliet finds out that Romeo is a Montague.
On her balcony after the party, Juliet wrestles with the big problem. "O Romeo, Romeo, wherefore art thou Romeo?" she asks. In other words, why does Romeo have to be Romeo Montague, a guy she's supposed to hate?
Romeo pops out of the bushes and promises to change his name if only Juliet will love him. This is obviously a little bit of a shock to Juliet. But she quickly gets over her surprise, and the two lovers decide that the family feud doesn't matter – they have to be together.
The two of them enlist the help of Juliet's nurse and Romeo's confessor, a priest named Friar Laurence. The Friar agrees to marry the two of them in hopes of resolving their families' feud. Less than twenty-four hours after they've met, Romeo and Juliet are tying the knot in secret at Friar Laurence's church.
Meanwhile, Tybalt is so furious at Romeo's invasion of Capulet territory (the party; he doesn't even know about Juliet) that he's decided he has to challenge Romeo to a duel. This is going to be a problem.
Romeo enters with a big just-married smile on his face – and finds Tybalt waiting for him. Tybalt insults him to his face, which would ordinarily make Romeo whip out his sword and get ready to fight. But Romeo knows that Tybalt is his wife's cousin, so he tries to ignore the insult and avoid fighting. To Romeo's friends, this looks like Romeo is being a coward. So Romeo's best friend Mercutio says he'll fight Tybalt instead. When Romeo tries to break up the fight, he only succeeds in getting in Mercutio's way at a crucial moment. Tybalt stabs Mercutio and runs away. Mercutio realizes he's dying, and he blames Romeo for interfering. Then he lashes out at both the Capulets and the Montagues for the whole situation. "A plague on both your houses!" he curses (3.1.111).
Romeo feels like he is to blame for his best friend's death, and he goes crazy. When Tybalt comes back, Romeo challenges him to a duel and kills him. Romeo blames his love for Juliet for making him refuse to fight Tybalt – which led to Mercutio's death. Juliet, meanwhile, finds out that her husband has just killed her cousin. For a while, it looks like the feud is going to pull the lovers apart.
But Juliet's loyalty to her new husband wins out over her feelings for her cousin. The lovers have another problem, though: as punishment for killing Tybalt, Romeo has been banished from Verona. Both Romeo and Juliet cannot cope with the idea that they will not be able to see each other. Death, they argue, is better than living separated from each other. Faced with two hysterical lovers, the Friar and the Nurse figure out a way for Romeo and Juliet to spend one night together before Romeo leaves for Mantua, a nearby city.
Romeo and Juliet have one amazing night together. But Romeo has barely climbed out the window before Juliet's mother sweeps in with the worst possible news: Lord Capulet has decided that Juliet is going to marry Paris right away. Juliet flips out and refuses to marry him. This makes her father so angry that he lays out an ultimatum: either Juliet marries Paris, or he will throw her out of the house.
Juliet turns to her mother for help, but her mother won't do anything. Even worse, Juliet's Nurse tells her that she should forget Romeo and marry Paris. The Friar is Juliet's last hope. She threatens to commit suicide if he can't figure a way out of the mess that she's in. He comes up with a crazy plan: Juliet will drink a weird potion that will make her appear as if she's dead. In fact, she'll only be sleeping, and when she wakes up in her family tomb, he and Romeo will be there waiting for her. Juliet is so desperate that she thinks this is a good idea. So she drinks the potion, and the next morning her family finds her "dead."
Everything would still be fine – except that the letter the Friar sends to Romeo (the one explaining the whole fake death situation) never reaches Mantua. So when Romeo hears the news from Verona, he thinks Juliet is actually dead. He immediately decides to kill himself rather than live without her. He finds a poor apothecary and bullies him into illegally selling him some poison. Then Romeo immediately leaves for Verona.
When Romeo arrives at the Capulet tomb, Paris is there, mourning over his dead almost-wife. Paris gets in the way, so Romeo kills him. Then he breaks into the tomb and embraces his dead wife. She still looks as if she's alive, Romeo says, which almost kills the audience. But he has no way of knowing the truth, so he kisses Juliet farewell and drinks the poison.
The Friar shows up about one minute too late, just in time to watch Juliet wake up from her drugged sleep. She immediately looks for Romeo – and finds him lying dead next to her. The Friar hears noise from outside, and tries to convince Juliet to run away. But Juliet refuses to leave Romeo's side. The Friar exits, and Juliet takes Romeo's dagger and stabs herself.
When the citizens of Verona – including Romeo and Juliet's parents – come in, the two lovers are lying side by side, both dead. "See what a scourge is laid upon your hate / that heaven finds means to kill your joys with love," the Prince tells the Montagues and Capulets. The families realize what their hate has caused and end the feud.