Ra.One is a 2011 Indian science fiction superhero film directed by Anubhav Sinha, who co-wrote the film's script with Kanika Dhillon. The film stars Shahrukh Khan, Kareena Kapoor and Armaan Verma in the lead roles, and Arjun Rampal as the titular antagonist. Additionally, the film features Shahana Goswami, Tom Wu and Dalip Tahil in supporting roles, and a number of cameo appearances. The plot follows Shekhar (Khan), a game designer in London living with his wife (Kapoor) and son (Verma). He designs a motion sensor-based game in which the antagonist is more powerful than the protagonist. The villain escapes from the game into the real world, and begins to track down Lucifer (the gaming ID of Verma), the only player to have defeated him.

Development of Ra.One commenced in 2004 when Sinha was struck with the idea for the film while watching a television commercial. Official pre-production began in 2007, and was followed the principal photography which took place in India and the United Kingdom. The film was co-produced by Eros International and Red Chillies Entertainment. Ra.One cost an estimated 125 crore (US$24.94 million), making it one of the most expensive Indian films at the time of release. A further 52 crore (US$10.37 million) was spent on marketing, which included a nine-month publicity campaign, brand tie-ups, merchandise, theme-based video games and viral marketing. The film, initially expected to release on June 3, 2011, encountered problems including delays, soundtrack leaks and copyright hurdles which created concern about the preparedness of the film for release at its scheduled release date. Subsequently, the release was delayed to the five-day Diwali weekend beginning on October 26, 2011.

1 (one;  /ˈwʌn/ or UK /ˈwɒn/) is a number, a numeral, and the name of the glyph representing that number. It represents a single entity, the unit of counting or measurement. For example, a line segment of "unit length" is a line segment of length 1.

One, sometimes referred to as unity, is the integer before two and after zero. One is the first non-zero number in the natural numbers as well as the first odd number in the natural numbers.

Any number multiplied by one is the number, as one is the identity for multiplication. As a result, one is its own factorial, its own square, its own cube, and so on. One is also the empty product, as any number multiplied by one is itself, which produces the same result as multiplying by no numbers at all.

The glyph used today in the Western world to represent the number 1, a vertical line, often with a serif at the top and sometimes a short horizontal line at the bottom, traces its roots back to the Indians, who wrote 1 as a horizontal line, much like the Chinese character 一. The Gupta wrote it as a curved line, and the Nagari sometimes added a small circle on the left (rotated a quarter turn to the right, this 9-look-alike became the present day numeral 1 in the Gujarati and Punjabi scripts). The Nepali also rotated it to the right but kept the circle small. This eventually became the top serif in the modern numeral, but the occasional short horizontal line at the bottom probably originates from similarity with the Roman numeral Failed to parse (Missing texvc executable; please see math/README to configure.): \mathrm{I} . In some European countries (e.g., Germany), the little serif at the top is sometimes extended into a long upstroke, sometimes as long as the vertical line, which can lead to confusion with the glyph for seven in other countries. Where the 1 is written with a long upstroke, the number 7 has a horizontal stroke through the vertical line.

Shahrukh Khan (pronounced [‘ʃaːɦrəx ˈxaːn]; born 2 November 1965), often credited as Shah Rukh Khan and informally referred to as SRK, is an Indian film actor. Known as "The King of Bollywood", Khan has acted in over 70 Hindi films. He has won fourteen Filmfare Awards from thirty nominations for his work in Indian films and shares the record for the highest number of Best Actor awards with Dilip Kumar, eight wins. In 2005, the Government of India honoured him with the Padma Shri for his contributions towards Indian cinema.

After graduating with a Bachelor's degree in economics, he started his career appearing in theatre and several television serials in the late 1980s and later made his Hindi film debut in 1992 with Deewana. Early in his career he was recognised for his unconventional choice of negative roles in films such as Darr (1993), Baazigar (1993) and Anjaam (1994). Since then he has played leading roles in a wide variety of film genres, including romantic films, comedies, thrillers, action films, sport films, and historical dramas among others.