game theory vs theory of games

game theory and theory of games both are nouns.

Word	Noun	Adjective	Verb	Adverb
game theory	Yes	No	No	No
theory of games	Yes	No	No	No

As nouns, game theory and theory of games are synonyms defined as:

game theory and theory of games: (economics) a theory of competition stated in terms of gains and losses among opposing players

game theory (noun)	theory of games (noun)
(economics) a theory of competition stated in terms of gains and losses among opposing players	(economics) a theory of competition stated in terms of gains and losses among opposing players