delusion vs head game

delusion and head game both are nouns.

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

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

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

Other synonyms of delusion include illusion.

delusion (noun)	head game (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