I use the words of Gygax for rules.lawyers...

> “It is the spirit of the game, not the letter of the rules which is important. Never hold to the letter written, nor allow some barracks room lawyer to force quotations from the rule books upon you, if it goes against the obvious intent of the game. As you hew the line with respect to conformity to major systems and uniformity of play in general, also be certain the game is mastered by you and not by your players. Within the broad parameters given in the Advanced Dungeons & Dragons volumes, you are creator and final arbiter. By ordering things as they should be, the game as a whole first, you campaign next and your participants thereafter, you will be playing Advanced Dungeons & Dragons as it was meant to be.”

Dungeon Master’s Guide (page 230), Gary Gygax


In practicality, I generally make lots of tiny modifications. Increase a monster stat here, change a power there. But even before that, at session zero, I explain that the game I run is about story. The group as a whole will, together, forge an epic story based on our actions. Rules are guidelines, and if something makes sense for the story and setting but bends or breaks a rule, so be it. Generally, players are in board when I present it that way.