Chuck Jones’ Rules for Writing Road Runner Cartoons

2. No outside force can harm the Coyote -- only his own ineptitude or the failure of Acme products. Trains and trucks were the exception from time to time.

5. The Road Runner must stay on the road -- for no other reason than that he's a roadrunner.

8. Whenever possible, make gravity the Coyote's greatest enemy.

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Chuck Jones’ Rules for Writing Road Runner Cartoons | Mental Floss