In "The Wedding Ringer," Jimmy (Hart) provides best man services for socially challenged guys, who – for whatever reason – have no one close enough to agree to stand by them on the day of their wedding. Doug (Gad) a groom-to-be, has found himself in just such a situation, but, to make matters worse, he fabricates the names of not only a best man but nine groomsmen as well. When all else fails, Doug seeks out Jimmy’s services to carry out a charade designed to make Doug look his best, but threatens to destroy everything if it fails.

Source : tmdb