Bad start to card game (6)
I believe the answer is:
crummy
'bad' is the definition.
'start to card game' is the wordplay.
'start to' says to take the initial letters.
'game' becomes 'rummy' (rummy is a kind of game).
The first letter of 'card' is 'c'.
'c'+'rummy'='CRUMMY'
(Other definitions for crummy that I've seen before include "Dirty and inferior" , "Very bad" , "Poor" , "Inferior (colloq.)" .)