Game is even, there’s nothing in it (6)
I believe the answer is:
quoits
'game' is the definition.
(I know that quoits is a type of outdoor game)
'even there's nothing in it' is the wordplay.
'even' becomes 'quits' (as in 'call it quits').
'there's nothing' becomes 'o' (I've seen this in other clues).
'in it' means one lot of letters goes inside another.
'quits' placed around 'o' is 'QUOITS'.
'is' acts as a link.
(Other definitions for quoits that I've seen before include "Game with rings, played on board ship, perhaps" , "Rings-over-post game" , "Game with rings, played on deck perhaps" , "Game using rubber rings" .)