The bottom line is that star power can easily make a hit out of a good movie that, without a big name star, no one outside of the actors’ immediate families would ever see. Sometimes, star power can even make a hit out of a mediocre move.
If, however, a movie truly stinks, it doesn’t matter who is in it. Movie stars cannot raise the dead, although many of them think that they can walk on water.
This is mostly true, but a lot of it depends on the movie.
The biggest name in American Graffiti was Ron Howard. The two biggest stars in Star Wars were Peter Cushing and Alec Guinness. The rest of the cast were selected specifically because they were no-name actors. Both of these were monster hits.
And, everyone laughed when they saw previews of Bruce Willis in Die Hard, but that turned him from a TV star into a major box office star. Same for Alan Rickman. This was a movie zero big-name stars, yet it was a huge hit that spawned several sequels.
If, however, a movie truly stinks, it doesn’t matter who is in it. Movie stars cannot raise the dead, although many of them think that they can walk on water.
This is 100% true. But, like I said before, being in a stinker doesn't really affect a star's bankability. There isn't an actor in Hollyweird who hasn't made a box-office bomb, even Harrison Ford. Remember "Frantic"? Man, what a waste of celluloid that was.