The crux of the matter; also, the main goal. For example, Getting them to admit they're wrong—that's the name of the game, or Parents don't approve of a coach who insists that winning any way one can is the name of the game. This rhyming idiom uses name in the sense of “identity.” [Mid-1900s]
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.