Guybrush Ulysses Threepwood kickstarts his dream of becoming a pirate on Mêlée Island. Mistaken for a flooring inspector, he sets out to complete The Three Trials: Swordplay against Carla the sword master, Treasure Hunting by finding buried treasure with a dance pattern, and Thievery by stealing the Idol of Many Hands from Governor Elaine Marley's mansion.
During his adventure, Guybrush develops a fondness for Elaine, the governor. He acquires the idol but is sentenced to death by Sheriff Shinetop. Using his ability to hold his breath underwater for ten minutes, he escapes and witnesses a ghost ship sailing away.
Having completed the trials, Guybrush finds the Scumm Bar deserted except for a weeping chef, who informs him that LeChuck, the ghost pirate, has kidnapped Elaine. Determined to save her, Guybrush gathers a crew, acquires a ship called The Sea Monkey, and sets sail for the legendary Monkey Island in a race against time to rescue Elaine from her perilous fate.
Guybrush embarks on a series of tasks on the island. One day, he uses a primitive art catapult to knock bananas off a tree, inadvertently sinking the Sea Monkey ship. Guybrush retrieves a banana-picker from a cannibal village and gives it to Herman Toothrot in exchange for a key to the Giant Monkey Head, believed to be the entrance to LeChuck's secret lair.
Using the giant key, Guybrush enters the Giant Monkey Head, descends into a dark and hellish realm, and traverses a lava-filled maze. Guybrush finds that he is too late and LeChuck's ship has already set sail to prepare for his marriage to Elaine on Mêlée Island.
With the help of Herman Toothrot's secret ship, Guybrush hastily returns to Melee Island to confront LeChuck. He rushes to the church to disrupt the wedding, unknowingly interfering with Elaine Marley's plan to escape and defeat LeChuck herself.
Guybrush uses the Voodoo Root Beer on LeChuck, causing him to explode into countless pieces. Guybrush made sure every person in the Caribbean knew of his deeds, albeit with some exaggerations, making himself seem the brave hero.