Bottom line: The winner takes it all.

What could be one's casual loss could turn into a life-changing gain for another. Whether it is luck at play or sheer chance, it changes everything. Like in Zoya Akhtar's multi-layered directorial debut, fortune rolls outs its dice in its central protagonist Vikram's (played by Farhan Akhtar) favour. Roles intended for X lands in Y's lap changing the dynamics of both -- a secure and obscure career.

rediff.com takes a look at Bollywood's history of original choices versus lucky replacements.

Amitabh Bachchan, Zanjeer

Everyone knows Prakash Mehra's incensed Zanjeer made a superstar out of a virtually unknown Amitabh Bachchan (back then). But the role of Inspector Vijay Khanna, despite its inseparable association and intense portrayal with/by Big B was not originally his.

Mehra, first, offered the part to Dharmendra. Apparently, the original action star after dillydallying a bit realised he was too busy to start the project.

Next, the director approached Dev Anand. But the evergreen legend's request to turn Zanjeer into some sort of a musical didn't find favour in Mehra's sensibilities.

Raaj Kumar was next on his wish list. But the Jaani star wanted him to film the story in Chennai, whereas Zanjeer was written keeping Mumbai's crime-laden backdrop in mind.

Finally on Pran's (who plays the memorable Pathan in Zanjeer) insistence, Mehra zeroed in on Bachchan. With all his films crashing like a house of cards at the box-office, AB was contemplating shifting to his native Allahabad.

Luckily for him and us, he didn't have to. The film's success marked a glorious beginning in the actor's career while giving him the enduring epithet of 'angry young man.'

Text: Sukanya Verma