lucky dip vs random sampling

lucky dip and random sampling both are nouns.

Word	Noun	Adjective	Verb	Adverb
lucky dip	Yes	No	No	No
random sampling	Yes	No	No	No

As nouns, random sampling is a hypernym of lucky dip; that is, random sampling is a word with a broader meaning than lucky dip:

lucky dip: a selection or decision purely at random
random sampling: the selection of a random sample; each element of the population has an equal chance of being selected

lucky dip (noun)	random sampling (noun)
a game in which prizes (e.g., candies or coins) are concealed in a container and for a small sum a player can draw one out at random	the selection of a random sample; each element of the population has an equal chance of being selected
a selection or decision purely at random