The most important skill I ever learned as a Dungeon Master was how to Fudge It™. I cannot overstate the value of this skill. It has saved numerous sessions, countless player lives, and kept friendships alive that might otherwise have been destroyed by the capricious nature of small plastic random number generators. Yes, I am being somewhat over-dramatic. No, it is not nearly as over-dramatic as you probably thing. I’m a bit of an oddity when it comes to RNG using dice since I tend more towards extremes than is statistically likely (based on a log book of rolls I kept for two years of daily rolls for science purposes combined with weekly rolls for D&D purposes using a variety of dice and rolling surfaces).
Given that each roll of the standard RNG polyhedral (a d20) is always a one-in-twenty chance of any given number without any relation to the rolls previous, this is hardly conclusive evidence. Nevertheless, I soon discovered that I either needed to make every roll to even the odds, or I needed to learn to fudge the numbers as they came so my players wouldn’t accidentally get killed as a result of some nameless mook rolling three natural twenties (a phrase describing when a twenty-sided die ends its roll with the twenty facing up) in a row. In most D&D campaigns, repeated natural twenties means some kind of incredible success for the character that rolled it. In combat situations, it usually means automatic death for the target of the attack.
Fudging It™ has more applications than simply correcting errant probability. If my players throw me a curve ball during a session and I need to correct on the fly, you can safely bet I’ll be making it up as I go along. A lot of my favorite parts of the campaigns I’m running are a result of my decision to abandon the rules and just wing it as I go. I literally built an entire campaign around the idea of deviating from the rules everywhere I can without undermining player ability and just making the funniest things I can think of happen in any given situation. At the Orchestra and surrounded by the upper class? Well, get ready for a bunch of Phantom of the Opera style vampires to attack and the only tuba player left in existence (BLORNTH THE TUBA PLAYER was the only tuba player to survive the tragic battle of the bands) to use his magically enchanted tuba to batter vampires to death before eventually spewing a gout of fire out of the end to rival that of any dragon.
I remember the first campaign I ran and how hard it was on the players to deal with my weird probability. I wasn’t very good at fudging things back then, so the healer accidentally died, the archer fell off a cliff (and then teleported over the bard in an attempt to save himself only to nearly kill the bard instead) to his death, and the bard accidentally killed a zombie so hard he killed himself as well. I learned a lot running that campaign and have improved as a storyteller so that I can Fudge It™ at a moment’s notice.
Now, in order to properly Fudge It™, there’s a process involved. The exact steps vary from person to person and situation to situation, but it usually involves some kind of disbelieving chuckle on the DM’s part at the sheer absurdity of the moment followed by some silent bargaining with the dice gods. After that, solutions are proposed and discarded in rapid succession until the DM settles on an acceptable outcome that either allows the players to continue without knowing something was amiss or allows them their choice of fates. Not all DMs choose to Fudge It™ and that is their right. Sometimes, in a harsher setting, it even makes sense to be as brutal as possible, though it might be better to Fudge It™ and make things slightly more brutal.
That’s the important thing to know, I suppose. Fudging It™ isn’t just for fixing problems. It also works great as a way to create problems or bump up the difficulty of an encounter if the players aren’t having any trouble with it. It is incredibly versatile and I recommend picking up the skill.