The problem was rats, too few rats. Director Werner Herzog envisioned thousands of them running through the streets of Delft and across a square for one scene of "Nosferatu" (1978). Delft was too tidy, and rat special effects would not be convincing. But the town's council had just spent a lot of money ridding the town sewers of rats and didn't want to see them return. The solution: An agreement to let the rats run -- and to take extraordinary precautions to keep them out of the sewers [source: Kawin].

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Line producers may have to manage rain for shooting films. See more movie making pictures.

Another problem was rain, too much rain. When pouring rain spoiled the chance for scheduled sunny-day shooting, filming on "Avalon" (1990) headed for a different location. That meant moving the company, the equipment and the trucks. But on the way there, the line director got a call. The director and producer now wanted to shoot the scene in winter. They'd film in the rain and make it look like snow. The solution: The line producer turned everyone around, and they headed back [source: Crouch].

These are the situations that bedevil line producers. Whether they're finding room in the budget for rat wranglers or turning on a dime to meet unanticipated demands, line producers have a challenging career. They develop the initial production budget for a film, work to secure the crew and equipment needed and then oversee expenses and scheduling day to day to make sure the film says on time and on budget -- while handling any crises that may occur along the way [source: Producers Guild of America].

What exactly do line producers do? And what skills does a line director need? Let's start with a closer look at the line producer's responsibilities.