KarinsDad said:
Actually, I do not consider that a mistake.
. . .
I'd rather lose a hundred NPCs (they are a dime a dozen) than lose a single player because he felt that I was unfair as a DM.
It's cool to let the dice fall as they may, as the saying goes, because yes, you do get really weird stuff sometimes. And also, it's okay to fudge dice, if it helps a cool situation. It all comes down to what's best for drama. Case in point, I ended up designing the entire end of my last campaign based on a bizarre roll.
One PC had a history, only loosely fleshed out, with an NPC knight who hated the PC's family. The NPC knight was trying to frame the party and get them killed, and the PCs were fleeing the city. They stop to get some of their gear from an inn, giving the city guards time enough to block the two main gates. The party tries and fails to sneak out, so a melee begins, and I'm perfectly willing to let them escape, and to let the entire city's guards die; the encounter was designed so that the PCs got frustrated with the government the city belonged to, thus guiding them toward allying with another group further down the road.
So what ends up happening is that the NPC knight engages the PC he hates in combat, and the knight is holding his own until he gets held and falls to the ground. They don't have time to coup de grace him officially, but he's low on hit points, so if they hit even once, he'll probably die. There's an enemy mage about to take his action, and only one PC gets to go before him. He makes an attack, and I say, "He can only miss on a 1," so of course he rolls a natural 1, in plain sight of everyone.
He misses, and the enemy mage gets off a wall of force to seal off the fallen knight and protect him, so the PCs flee and leave the knight barely alive.
I mulled over this for a while, wondering what I could do with the knight who I'd kinda thought would die anyway. I ended up tying him in with the ending of the campaign, making it good fortune on the PCs part that they hadn't killed him (killing him would have condemned the PC's soul to hell; part of a weird arrangement with a demon).
So that time, letting the dice work oddly was good. But other times, like when the PC challenges the villain to single combat, and charges in with a battle cry, prepared to fight for victory, and then he rolls, like, 2 points too low to hit, or something. So you fudge, to keep up the drama, and to keep the player from feeling like a fool. And when you completely underestimate the damage dealing power of the party so that the villain will die in the second round of combat, you fudge to give him higher AC and more hit points, so that the final battle isn't anticlimactic.
A DM should never break the rules just because he's clingy to a particular 'cool' villain; you do it for the sake of the story, and for the entertainment of your friends. If you were a member of a group of 1st levelers who went through a Living Greyhawk game at GenCon meant for 8th level PCs, then I probably was your DM, and I'm proud of the occasional *ahem* fudge I made in that session so that you could be the heroes, rather than being mincemeat.