Growing up together, Mitch (Reynolds) and Dave (Bateman) were inseparable best friends, but as the years have passed they've slowly drifted apart. While Dave is an overworked lawyer, husand and father of three, Mitch has remained a single, quasi-employed man-child who has never met a responsibility he liked. To Mitch, Dave has it all: beautiful wife Jamie (Lesllie Mann), kids who adore him and a high paying job at a prestigious law fim. To Dave, living Mitch's stress free life without obligation or consequence would be a dream come true.
After a drunken night out together, Mitch and Dave's worlds are turned upside down when they wake up in each other's bodies and proceed to freak out.