Eastwood Rule 

Definition: A rule legislated by the Directors Guild of America that prohibits an actor or producer from firing the director and then becoming the director himself.

History: This was the Director’s Guild’s response to actor Clint Eastwood firing director Philip Kaufman from the Civil War shoot-‘em-up “The Outlaw Josey Wales” (1976). The two men had, as they say, artistic differences. Kaufman’s insistence on authenticity—from spitting tobacco to calling it “tobacky”—clashed with Eastwood’s Spaghetti Western cool.

But more important was the metaphorical head-butting over co-star Sondra Locke. Eastwood hired Kaufman's squeeze over Kaufman’s objections, then decided Kaufman’s presence made a crowd.