Since many films are made without big stars, that seems like an overly restrictive definition.
If somebody's aunt dies and leaves them a billion dollars and they say, "Let's make this film", then it goes into production.
Of if an exec at HBO or wheverever greenlights it, it's on its way. Cast added later.
But yeah, that's "development hell". Everything being churned around except the money.
The rules for TV movies, including cable movies are different, because their audience is different, but you'd be mistaken if you think that casting is irrelevant to the process.
It's a different audience and so different names carry different weight, but the names matter on TV too.
And for certain kinds of movies of a certain budget -- if you're making "Saw" -- the stars aren't nearly as important.
But "Saw" had Cary Elwes and Danny Glover and Dina Meyer in it. That's a respectable cast.
There's a difference between "stars" as in Tom Cruise and "stars" in the sense of -- we've got to have names of a certain level of recognizability in order to be able to sell this movie in certain markets -- and lacking those recognizable names, the movie isn't going to get green lit.
Danny Glover may mean nothing to you or me -- but to a foreign distributor, or to someone releasing a movie on DVD, that's a recognizable name that can be put on a poster or on the front of a DVD -- it's the difference between a movie they're willing to release and another movie with a no-name cast that isn't promotable.
Once the first movie hit big, it really didn't matter -- because after that, they could sell it off the strength of the first movie.
Of course, once Saw hit big, then you could sell other movies like Saw -- just on the strength of Saw.
So you end up with movies like Hostel and the rest, also with very minor stars, riding that wave.
But you always have a package. A script, a director, a producer, and generally a star or stars.
Nobody, not HBO or anybody else in the business, just reads a script and gives a greenlight.
As for somebody being left a billion dollars -- sure, if you're rich enough, you can do what you want, including making your own movie. You can even rent the theaters yourself and distribute it yourself -- and if you really want, you can even pay people to sit in the seats and watch it.
But that's not how movies are generally made.
NMS