by-numbers

adjective

1. informal.
   done in an uninspired, simplistic, or formulaic way

Word History and Origins

Origin of by-numbers¹

C20: from painting by numbers , a method of painting a picture in which the colours to be used are indicated by numbers

Example Sentences

Many Republican wags, such as David Frum and Erick Erickson, are already onto the Boehner paint-by-numbers game of the “Pledge.”

From The Daily Beast