Fig. 5 - Liz Lemon from 30 Rock
The Straight Man is extremely common, but should be avoided. The straight man never gets to have any fun, they are a representative of the audience in the face of the dumb character. Every other character is doing silly things while the straight man is left to look aghast at the insanity.
Examples
- Liz from 30 Rock
- Michael Bluth from Arrested Development
- Penny from Big Bang Theory
- Jeff from Community
- Annie from Community
The problem with the straight man is because they represent the audience, reality, and common sense, they are often a party-pooper. The other characters don't have the restrictive bounds of intelligence and are able to be dumb and get into shenanigans. The straight man can only look on disapprovingly.
The straight man can be a useful character type when they are eventually allowed to join in on the fun. Liz is often the normal character in 30 Rock, but sometimes she gives in and goes a little crazy. This personality change can be incredibly funny because the audience knows that Liz should know better but she's temporarily impaired due to an obsession.
Community constantly changes the straight man in each situation, just how they trade off the dumb character. Jeff might be sarcastically mocking the crazy thing a character is doing until he recognizes something he wants. Then he joins in completely. Annie may understand that the situation is dumb until a failing grade is threatened; then she is in as well.