Why, often in film credits, are the actor’s and character’s name often written as, for example, “Ian McKellen – Gandalf (as Ian McKellen)”, but only for certain cast members?

Question

I’ve seen this a lot on IMDB, and this was just an example using more well-known names. For a direct example, I was looking up the cast for the 1999 film, DragonHeart: A New Beginning, and the lead actor, Chris Masterson, is listed as “Christopher Masterson – Geoff (as Christopher Masterson)”, and another character is ” Vladimir ‘Furdo’ Furdik – Sentry (as Vladimir Furdik)”, but only those 2 actors were listed that way. What does it mean that their character is “as the actor”, but it’s only true for them and not anyone else in the cast?

In: 80

Answer 1

The two names which are listed are the one the actor is commonly known as and the other is how the credit in the film is given. The movie may list him with one name, IMDb or other sources May refer to them by another name. This is especially common for actors who have changed their screen names during their career.