Thesps Jay Baruchel (“Undeclared”) and Joel Michaely (“But I’m a Cheerleader”) have been added to the roster of Roger Avary’s “The Rules of Attraction.” Pic, based on the Brett Easton Ellis novel, is lensing in L.A. James Van Der Beek and Shannyn Sossamon star. Baruchel bows Sept. 18 in Judd Apatow’s Fox series “Undeclared”; Michaely is next featured in a trio of pics: “Rent Control,” “L.A.X.” and “Repli-Kate.”