“Once upon a time” in Beijing. Anyone who wants to marry Princess Turandot (a “divine beauty” with a heart of stone) must solve three riddles, and if they fail, they lose their head. An unknown prince succeeds, but Turandot refuses to marry him. So, the stranger makes her a counteroffer: if she can guess his name before dawn, she can have him executed, otherwise, she must honour their agreement.
Act 1
A Mandarin man in Beijing relays Princess Turandot's decree to the people: any prince seeking to marry her must solve three riddles, or face beheading (as witnessed with the latest failed suitor from Persia). While the crowd awaits the next trial, Calaf (an exiled prince in disguise) reunites with his blind father Timur, accompanied by the loyal slave girl Liù. However, when he sees Turandot, he falls in love with her at first sight and decides to try his luck in turn. The three imperial ministers (Ping, Pang, and Pong) try to dissuade him, while Liù (who has always loved him) begs him not to risk his life. But their pleas are futile. After asking Liù to take care of the elderly Timur, Calaf bravely steps forward to face the perilous trial.
Act 2
Following Ping, Pang, and Pong's reflections on conditions in China, the trial unfolds with the Emperor, Turandot's father, in attendance. Initially, the princess expresses her desire to execute all suitors to avenge the violent death of an ancestor, then poses the three riddles. Although Calaf solves them, Turandot refuses his marriage proposal. Consequently, the prince issues his own challenge: “Guess my name before dawn, and you may execute me. Otherwise, you must marry me”.
Act 3
As Beijing remains vigilant under Turandot's decree, Calaf waits for dawn, confident in his imminent victory. However, the ministers capture Timur and Liu, the latter choosing to kill herself in order not to divulge the secret of the man she loves. Liu's suicide deeply affects everyone, prompting Calaf to confront Turandot, managing to kiss her and thaw her icy heart. The princess confesses to him that she has loved him from the start. Calaf then reveals his identity, leaving his fate in her hands. As the people and court assemble, Turandot proclaims the stranger's name as “Love”. The sun rises and everyone celebrates the new royal couple.