fortune vs good luck

fortune and good luck both are nouns.

Word	Noun	Adjective	Verb	Adverb
fortune	Yes	No	No	No
good luck	Yes	No	No	No

As nouns, good luck is a hyponym of fortune; that is, good luck is a word with a more specific, narrower meaning than fortune:

fortune: an unknown and unpredictable phenomenon that leads to a favorable outcome
good luck: a stroke of luck

Other hyponyms of fortune include fluke, good fortune.

As nouns, good luck is a hyponym of fortune; that is, good luck is a word with a more specific, narrower meaning than fortune:

fortune: your overall circumstances or condition in life (including everything that happens to you)
good luck: an auspicious state resulting from favorable outcomes

Other hyponyms of fortune include good fortune, luckiness, providence, bad luck, ill luck, misfortune, tough luck, failure.

fortune (noun)	good luck (noun)
an unknown and unpredictable phenomenon that causes an event to result one way rather than another	an unexpected piece of good luck
an unknown and unpredictable phenomenon that leads to a favorable outcome	a stroke of luck
a large amount of wealth or prosperity	an auspicious state resulting from favorable outcomes
your overall circumstances or condition in life (including everything that happens to you)