head game vs delusion

head game and delusion both are nouns.

Word	Noun	Adjective	Verb	Adverb
head game	Yes	No	No	No
delusion	Yes	No	No	No

As nouns, head game and delusion are synonyms defined as:

head game and delusion: the act of deluding; deception by creating illusory ideas

Other synonyms of head game include illusion.

head game (noun)	delusion (noun)
the act of deluding; deception by creating illusory ideas	the act of deluding; deception by creating illusory ideas
	a mistaken or unfounded opinion or idea
	(psychology) an erroneous belief that is held in the face of evidence to the contrary