Tragicomedy at its finest; a treatise on how real life goes down:

Incompetent person, e.g. Jerry Lundegaard, has a flight of fancy. Said fancy gets corrupted by the real world. Said incompetent thinks they are competent enough to breach the reality gap. Said breach attempt degenerates into pointless acts of brutality, harming (usually innocent) others. Big mess. Someone competent, e.g. Marge Gunderson, must clean it up.

Dark hilarity ensues.