Subhash Ghai's original choice for the villain's role (Dr. Dang) was Amrish Puri, but the film-maker opted for Anupam Kher instead. Reason: "Amrish has been killed so many times on screen earlier that people wouldn't be interested in watching him get killed yet again," Ghai had revealed then.
The confrontation scene between Naseerudin Shah and Dilip Kumar was actually shot with the two actors separately. Naseer delivered his lines to a stand-in of Dilip Kumar (whose back was to the camera) while DIlip Kumar delivered his lines to a stand-in of Naseer. Shah was very upset with Subhash Ghai over this decision, feeling that the director had cheated him out of having a scene with the legendary actor Dilip Kumar, and vowed never to work with Ghai again.
Subhash Ghai wanted Rajnikanth for the film. He had written a role just for him. But it was Anil Kapoor and Boney Kapoor who convinced Ghai go sign Naseeruddin Shah. Anil felt having Naseer in the film would add respectability to the project.
The massive jail that Rana Vishnu Pratap (Dilip Kumar) is in-charge of was built specifically for this film and then later destroyed for the film.
On finally meeting his childhood hero Dara Singh, Naseeruddin stated "When I finally met him while we were shooting Karma (1986), I held his hand and told him, 'Sir, I am so happy to meet you, you don't know how much of your work I've seen,' and he goes, 'Oh no, you are a very serious actor,' and I rattled off a list of 25 movies I had actually seen, including one called Trip to Moon-Chand Par Chadayee (1967). He asked me how I could have watched it as the movie never released. I told him that I took a three rupee ticket to see it in Rialto cinema in Mussoorie. Apparently, the film had some abandoned wrestling moves and Helen aunty's dances put together and idiots like me went to see it".