There are basically two kinds of people in the world: those who organize their potluck parties down to the plastic cups and extra ice, and those who shrug their shoulders and say 'Oh, bring whatever. I'm sure it will all work out!'
The Control Freak
makes charts and lists and assigns every aspect of the evening down to the flavors of the salad dressings and oven timing. He/she is on top of all details and runs a tight potluck ship.
Organized but Mellow wants to avoid the three-taco-dips-but-no-dessert kerfuffle but is not interested in controlling things beyond that. He/she will assign guests a basic category (appetizer, main, dessert, cups and ice) and then relax.
Oh, Bring Whatever! believes that half the fun of a potluck is seeing what people show up with, so he/she stays completely hands off. He/she embraces the three-taco-dips-but-no-dessert possibility and upholds the notion that the whole reason to throw a potluck is to avoid working too hard.
I Don't Host Potlucks probably has many reasons for this and will hopefully share a few of them in the comments.
Related: Potluck Etiquette: What Are your Rules?
(Image: This Magazine)