This is a list of archetypes that I identified after watching too many sitcoms (especially US ones), over the years. It isn't a definitive list, the definitions are self-invented, arbitrary and generalised and the examples below may not be an precise match for a given archetype. In practice any self-centred character (or any character) in a sitcom may display aspects of one or more of these archetypes. Also it is always best to write real, true-to-life characters and not two-dimensional archetypes or stereotypes.

IDIOT SAVANT

• A nutty friend who speaks fundamental truths.
• A character that goes through life with his or her own particular bizarre rules.
• They manage to have a good life without having to work for it.
• Weird things happen to them.
• They are prodigiously fortunate or unfortunate.
• They have exaggeratedly human reactions .
• They never look for or find the easy way out of any situation .
• Their complex way of doing things has a way of working out.
• They have a logical reason for what they do and it might even sound sensible.

Examples
Kramer (Michael Richards) - Seinfeld
Nick (Kris Marshall) - My Family
Phoebe & Joey - Friends

THICK-SKINNED OAF

• THEY DON'T LISTEN; THEY DON'T LEARN; THEY DON'T GROW.
• They are incredibly selfish, thinking only of their own comfort.
• They are petty, vindictive and essentially childish.
• They are not able to relate to the real world and exist in a one-person universe.
• They think only in terms of self-gratification and may commit most of the seven deadly sins.
• They've probably got a really strange or messed up relationship with their parents.
• You can spend an hour berating them for something and they'll fail to acknowledge what you said.
• Terrible things happen to these people but they are never quite brought low enough that they realise that they must change.
• They always bounce back.
• They've always got an excuse

Examples
George (Jason Alexander) - Seinfeld
Cartman - South Park
Louise (Kathryn Drysdale) - Two Pints of Lager and a Packet of Crisps
Ross (David Schwimmer) - Friends

WISECRACKER

• Almost a thick-skinned oaf but cleverer and witty.
• They criticise but do it so that people laugh.
• They judge but aren't actually cruel.
• Their joking is often a cover for deep-seated insecurity.
• They are compensating for a past they were bereft of cool
• They aren't that good at personal relationships.
• They are honest, moral and truthful (eventually).
• They'd like to be heartless but are tripped up by their own good natures.
• They are practical jokers but can't bear to see their friends suffer too much.

Examples
Chandler (Matthew Perry) - Friends
Roz Doyle (Peri Gilpin) - Frasier
Any redheaded secretary in an office based sitcom

WACKY BOSS

• They have an air of the Deus Ex Machina about them
• They stroll through the office at the beginning of an episode making impossible demands.
• Then stroll through the office at the end fixing the problems they caused.
• They are powerful but childlike.
• They will occasionally have a King/Court Jester relationship, with any Idiot Savant to hand.
• They will have power struggles against Wisecrackers.

Examples
CJ (John Barron) - The Fall And Rise Of Reginald Perrin
Holly (Norman Lovett / Hattie Hayridge) - Red Dwarf
Jack Gallo (George Segal) - Just Shoot Me

STILL CENTRE

• Often a fairly passive character in a series.
• Weirdness happens around them but they keep their sanity
• The sensible person who restores order at the end of the episode
• Avoid having one of these. At least give them a foible or weakness to make them interesting

Examples
Susan Walker (Sarah Alexander) in Coupling
Mel Steele (Sarah Alexander) in Worst Week of My Life