Had races organised as party game (8)
I believe the answer is:
charades
'party game' is the definition.
(I've seen this in another clue)
'had races organised' is the wordplay.
'organised' indicates anagramming the letters.
'had'+'races'='hadraces'
'hadraces' anagrammed gives 'CHARADES'.
'as' acts as a link.
(Other definitions for charades that I've seen before include "Game in which answers are acted out" , "Miming games" , "Party guessing game" , "Games like this" , "Miming parlour game" .)