In a parlay bet where the returns from a bet is used to wager the next one, a draw no bet will only cut the parlay off if the opposing team wins the game. If your backed team wins, you will receive your stake plus your win, and it goes on to the next game. If there is a draw, you will receive just your stake back to be used in the next game. But if the opposing team wins, you will lose your stake and cut off the progression of the parlay.