Lottery
Lottery (noun) /ˈlɒt.ər.i/ US /ˈlɑː.ţɚ-/
a gambling game in which some numbered tickets are sold and some people are selected as the winners with prizes – a situation or activity that is dependent on chance or luck – bingo – risk – chance:
He won the lottery the very first time he attended it.
Antonym: certainty