King's Quest VI: Heir Today, Gone Tomorrow is an adventure game set in the fictional Land of the Green Isles. Players control Prince Alexander as he navigates a series of diverse islands, each with unique themes inspired by various mythologies and literary works. The game begins with Alexander's shipwreck on the Isle of the Crown, where he discovers that Princess Cassima, whom he seeks, is being held captive by the scheming vizier Abdul Alhazred. To rescue Cassima and thwart the vizier's plans, Alexander must explore the kingdom, solve puzzles, and uncover secrets across multiple islands, including the Arabian Nights-themed Isle of the Crown, the Alice in Wonderland-inspired Isle of Wonder, and the mythological Isle of the Sacred Mountain. The game features a magic map for travel between islands and includes hidden areas that expand the narrative and gameplay possibilities.