Plot
In the frame story, a grandfather reads a novel called The Princess Bride to his sick grandson, who reluctantly listens.
Buttercup is a young woman living on a farm in the kingdom of Florin. Her farmhand Westley obediently follows her stringent commands, always responding with "As you wish." Buttercup eventually realizes Westley is saying he loves her, and she reciprocates his feelings. Westley leaves to seek his fortune overseas so they can marry, but his ship is attacked by the Dread Pirate Roberts, who infamously leaves no survivors.
Five years later, Buttercup, still grief-stricken, is forcibly betrothed to Florin's arrogant Prince Humperdinck. Before the wedding, she is kidnapped by crafty Sicilian criminal Vizzini and his accomplices: gentle Turkish giant Fezzik, and expert Spanish swordsman Inigo Montoya, who seeks a six-fingered man that killed his father. A masked man in black pursues them across the sea, as do Humperdinck and his soldiers.
Atop the Cliffs of Insanity, the man in black defeats Inigo in a sword duel and knocks him out, chokes Fezzik into unconsciousness, and kills Vizzini by tricking him into drinking poison. He absconds with Buttercup ahead of Humperdinck's party. When Buttercup identifies him as the Dread Pirate Roberts, she rebukes him for killing Westley and shoves him into a ravine. While tumbling down, he shouts, "As you wish!" Realizing he is Westley, Buttercup tumbles after him and they reunite. The couple then flees into the dangerous Fire Swamp to avoid Humperdinck's party.
In the Fire Swamp, Westley explains that the "Dread Pirate Roberts" is an inherited title. The previous Roberts spared and recruited Westley, then retired and passed the mantle on to him. Having found Buttercup, Westley intends to do the same. Humperdinck captures the couple at the Fire Swamp's exit, but Buttercup agrees to return with Humperdinck after he promises to release Westley. Humperdinck then secretly orders his advisor Count Rugen, the six-fingered man, to take Westley to his torture chamber, the Pit of Despair.
After a nightmare, Buttercup threatens to kill herself if Humperdinck marries her. He placates her by promising to find Westley, then privately confides in Rugen that he plans to murder Buttercup, which Vizzini failed to do, and subsequently declare war on the neighboring country of Guilder. To maintain the ruse, Humperdinck has his enforcers organize a "brute squad" to clear out the nearby thieves' forest. Fezzik, as part of the brute squad, finds Inigo drunk in the forest, sobers him up, and informs him of Count Rugen's existence. Recalling Westley's versatility and intelligence, Inigo and Fezzik search for him to help them kill Rugen.
Buttercup discovers Humperdinck's duplicity and labels him a coward. Enraged, he imprisons her and tortures Westley seemingly to death. Inigo and Fezzik follow Westley's screams to the Pit, discover his lifeless body, and take it to Miracle Max, a folk healer whom Humperdinck recently fired. Max declares that Westley is only "mostly dead", and after Inigo promises that Westley can humiliate Humperdinck, Max and his wife concoct a pill to revive him.
Fezzik and Inigo revive Westley with the pill, rendering him conscious but barely able to move. By impersonating the Dread Pirate Roberts, the three infiltrate the castle as the wedding begins and encounter Rugen, who flees with Inigo in pursuit. Despite an ambush from Rugen, Inigo kills him. At the wedding, Humperdinck impatiently rushes the ceremony, then sends Buttercup to her chambers. Before she can commit suicide, Westley intercepts Buttercup and reminds her that she never gave her vows, invalidating the marriage. Humperdinck discovers them and challenges Westley to a duel, but Westley intimidates Humperdinck into submission. Inigo reunites with the couple, and Westley offers him the title of Dread Pirate Roberts. The three escape on horseback with Fezzik, and as dawn breaks, Westley and Buttercup share a passionate kiss.
The sick grandson eagerly asks his grandfather to read him the story again the next day. His grandfather replies, "As you wish."
