The simple but strict rules for Road Runner cartoons.
1. Road Runner cannot harm the Coyote except by going "beep, beep".
2. No outside force can harm the Coyote -- only his own ineptitude or the failure of Acme products.
3. The Coyote could stop anytime -- IF he was not a fanatic. (Repeat: "A fanatic is one who redoubles his effort when he has forgotten his aim." -- George Santayana).
4. No dialogue ever, except "beep, beep".
5. Road Runner must stay on the road -- for no other reason than that he's a roadrunner.
6. All action must be confined to the natural environment of the two characters -- the southwest American desert.
7. All tools, weapons, or mechanical conveniences must be obtained from the Acme Corporation.
8. Whenever possible, make gravity the Coyote's greatest enemy.
9. The Coyote is always more humiliated than harmed by his failures.
10. The audience's sympathy must remain with the Coyote.
Charles Miller argues that John Hodgman's PC character in the Mac vs. PC commercials is like Wile E. Coyote...likable but inept. (via df)