"What if my players come up with a great idea, and I have no idea how to respond?" I asked. "I can’t plan for every path they might take ahead of time. Isn’t that impossible?"
Mentzer shook his head. A good DM doesn’t need to counter every clever idea with a clever rebuttal, he explained. Instead, they collaborate with players to find common ground, a place where both can be comfortable.
"Remember, the game master is part of the group," he said. "It is not an adversarial situation, though plenty of game masters run it that way. The game master has to be able to transcend his own desires and evolve. All of the members of the gaming group—and that includes the game master—have to feel like they’re winning.""
— David M. Ewalt, asking Frank Mentzer advice on running his first Dungeons & Dragons game - Of Dice and Men: The Story of Dungeons and Dragons and the People Who Play It. (via corruptionpoints)