Game of chance allowed to get in the way (8)
I believe the answer is:
roulette
'game of chance' is the definition.
(roulette is a kind of game of chance)
'allowed to get in the way' is the wordplay.
'allowed' becomes 'let' (I've seen this before).
'to get in' means one lot of letters goes inside another.
'the way' becomes 'route' (route is a kind of way).
'let' put into 'route' is 'ROULETTE'.
(Other definitions for roulette that I've seen before include "French gambling" , "Wheel of fortune" , "Gambling device" , "Wheel for the gambler" , "Gambling activity" .)