Lack support to control children's game (8)
I believe the answer is:
shortage
'lack' is the definition.
(shortage is a kind of lack)
'support to control children's game' is the wordplay.
'support' becomes 'shore' (I've seen this before**).
'to control' means one lot of letters goes inside another.
'children's game' becomes 'tag' (I've seen this before).
'shore' going around 'tag' is 'SHORTAGE'.
(Other definitions for shortage that I've seen before include "may put price up" , "Deficit" , "Need" , "Scarcity" , "Her goats (anag)" .)