UngeheuerLich said:if the DM is good, you won´t ever have an undeserved win. My rule as a DM can be described as following:
If the PCs don´t act as complete fools, they won´t die because of a very unlucky roll. If they do, bad luck hits them mercilessly... if they have particular good ideas they may get get some bonuses, which account for their good roleplaying.
Call it cheating or fudging or conditional bonuses of a different sort.
The fumble in the example above could have just hit the unconsciuos employer, and the luck bonus spent could have meant, that the enemy was so surprised, that he lets him go, or is even also hit by the arrow which shot right through the hostage...
and instead of a funeral, you could have brought him to a healer etc...
IMO DM fudging should be very rare and unnecessary. The rules themselves should never allow that the fate of a character or campaign relies on a single die roll.