Mumbai, Jan 5 (IANS) Acting in 'Rock On' was fun for Farhan Akhtar, but now it seems to have become a responsibility. The director-turned-actor says working in his sister's directorial debut 'Luck By Chance' is an extra challenge and he has to ensure its success.

'I'm not looking at 'Luck By Chance' as an opportunity to further my career as an actor. It is my sister's film and I am the producer. So it is very important for me to see 'Luck By Chance' work in totality,' Farhan told IANS.

Directed by Zoya Akhtar, the film also stars Hrithik Roshan and Konkana Sen Sharma and is scheduled for release in January-end.

The success of 'Rock On!' has made Farhan the most promising debutant actor of 2008. As the encomiums flow in, he tries hard not to get affected by the praise.

To compound his woes, Farhan plays a struggling actor in 'Luck By Chance'.

'In my first film, the unreleased 'Fakir', I played a member of a film unit. In 'Rock On!', I was a musician. Both were parts intrinsic to my personality. But the struggler in 'Luck By Chance' is someone I've seen outside.

'Every day these hopefuls wait outside buildings, by your car, at the foot of elevators and lifts, to get the attention of filmmakers. Every day they are prepared to be snubbed and humiliated. I've seen these guys' humiliation and desperation, but not experienced them first-hand. There's so much desperation to portray without making the character look in-your-face tragic.'

As a director, Farhan has hits like 'Dil Chahta Hai', 'Lakshya' and 'Don - The Chase Begins Again' to his credit.