Leading Indian actors and actresses must appear in a double role at least once during their careers to prove that they can portray two characters with the same face and different personalities. The two-for-the-price-of-one tradition has resulted in numerous films about identical twins and lookalikes. Dev Anand has Hum Dono (1962) to his credit, Dilip Kumar Ram Aur Shyam (the 1967 remake of the Telugu hit Ramudu Bheemudu), Hema Malini Seeta aur Geeta (1972), which inspired the remake Chaalbaaz (1989) with Sridevi, and Anil Kapoor Kishen Kanhaiya (1990). Amitabh Bachchan has played duplicates in Don (1978) and The Great Gambler (1979). Gulzar’s delightful comedy Angoor (1982), an adaptation of William Shakespeare’s The Comedy of Errors, has two sets of identical twins played by Sanjeev Kumar and Deven Verma.

Shah Rukh Khan has played double roles in Duplicate (1998), the remake of Don (2006) and Paheli (2005). In the April 15 release Fan, Khan plays a movie star and his troubled lookalike devotee.

The theme of doubles works best in movies about identical twins that are separated in their infancy, typically by a natural disaster or a conspiracy, and grow up in vastly different circumstances, only to be reunited by the moving hand of the scriptwriter. Twins suit the comedy and drama genres, but their fundamental strangeness and mysterious ability to act as human mirrors is tailor-made for the horror genre too. In Brian De Palma’s Sisters (1973), Margot Kidder plays Siamese twins who are separated in their adulthood. Danielle is passive while Dominique is aggressive, as a hapless admirer whose only crime is to be in the wrong place at the wrong time finds out. When a brave reporter (Jennifer Salt) sets out to investigate, the trail leads to a lunatic asylum run by a strange-eyed and sinister doctor.

The trailer of ‘Dead Ringers’.

David Cronenberg’s tellingly titled Dead Ringers (1988) offers a cerebral counterpoint to the schlocky pleasures of Sisters. In Dead Ringers, loosely based on a real-life case, identical twins fall in love with the same woman. Beverly and Elliot (a brilliant Jeremy Irons) are gynaecologists with a habit of sharing women, who remain blind to the deception. Tensions develop between the perfectly synced brothers when Beverly develops feelings for Claire (Genevieve Bujold), a neurotic actress with a rare cervical problem. While Cronenberg’s fascination with bodily deformities shows up in a nightmarish sequence in which Claire shares the twins’ bed, the movie goes beyond mere shock to explore the spiritual and psychological bonds that wrap the twins in a deadly embrace. In a reversal of Sisters, the twins in Dead Ringers seek to become one in order to erase their differences, with tragic results.

The idea that men or women can be linked by chance rather than a single zygote has created a related sub-genre of films about doubles. These duplicates do not emerge from the same womb but from a place that defies logic or simple explanations, and their strange encounters with each other and the world make for thought-provoking and even disturbing cinema.

In Krysztof Kieslowski’s beguiling contemporary fairy tale The Double Life of Veronique (1991), Irene Jacob plays Polish opera singer Weronika, who knows that she is not alone. She feels the presence of another person throughout her life, and one day, she sees her doppelganger in a moving bus.

Veronique’s life mirrors Weronika’s in bewildering ways. The women share passions, objects and traits – classical music, a marble, widowed fathers, visions of an elderly woman, and an unfathomable restlessness. The coincidences that link them are made clear by a puppeteer, who pulls the final strings that bring the women closer in spirit. Beautifully shot in febrile tones of lime-green and crimson, the movie sustains a feeling of transcendence and the uncanny throughout.

The trailer of ‘The Double Life of Veronique’.

A sudden and life-altering encounter with a mirror image also forms the basis of Jose Saramago’s The Double. The 2002 novel explores the events that unfold when a history teacher sees a man who looks just like him in a movie. Dennis Villeneuve’s version, Enemy (2013), stars the talented Jake Gyllenhaal as the two men who are identical in appearance. The screen adaptation also borrows from Franz Kafka’s Metamorphosis to suggest that the transformation of the characters after they meet each other is not only psychological but also physical.

The trailer of ‘Enemy’.

Duplicates are not only unnerving reminders of the irrational ways in which the world works. They can also inspire comedy. In Frank Oz’s hilarious Bowfinger (1999), Eddie Murphy plays a stuck-up movie actor and his dim-witted lookalike. Ramsey (Murphy) is appearing in a science-fiction movie directed by the inept filmmaker Bobby Bowfinger (Steve Martin) without his knowledge, but when Ramsey is consumed by the delusion that aliens are out to get him, he is replaced by amateur Jiff (Murphy again).

A clip from ‘Bowfinger’.

The idea of a personage being replaced by a commoner, either by accident or design, has endured since Mark Twain’s 1881 novel The Prince and the Pauper. While Charles Chaplin’s The Great Dictator gave a comic spin to the classic theme, Akira Kurosawa’s masterly Kagemusha (1980) is an altogether more sobering meditation on the compulsions and limitations of statecraft. Set in sixteenth-century Japan during a period of endless war, Kagemusha sets up its themes of power and hierarchy in its opening sequence. A thief (Tatsuya Nakadai) sits on the floor a few notches below the feudal lord Shingen and his brother, Nobukado. The siblings resemble each other, and Nobukado has occasionally impersonated his brother, but the thief is a dead ringer for the ruler. He is forcibly recruited as a kagemusha, or a shadow warrior, and is made to play the part when Shingen dies in battle.

The trailer of ‘Kagemusha’.

The thief eases himself into the role all too smoothly, and is a witness to the palace intrigue and the bloody battles that mark the three years he occupies the throne. The pretender turns out to have more honour and integrity than his feudal masters, but he is plagued by doubt. In a sequence that takes the movie’s use of bright and rich colours to an extreme, the thief has a nightmare about meeting his duplicate. Kagemusha was the main inspiration for Rajat Kapoor’s Mithya (2008), set in the Mumbai underworld and featuring Ranvir Shorey as the lookalikes.