There’s a gulf between GMing theory and actual GMing, and standing in the middle of that gulf is you, the GM. You decide how to bridge what you know about GMing and what you actually do at the gaming table, and for me this is one of the trickiest aspects of GMing.

I know a lot about GMing. I’ve been a GM for over 20 years, published two GMing books with the gnomes, blogged about GMing for five years, and written about GMing as an RPG freelancer. I think about GMing more or less all the time (that’s normal, right?).

…but when the rubber hits the road, sometimes it’s like the part of my brain that’s full of GMing theory just turns off. I make boneheaded calls. I fail to read the table. I write adventures or scenes that suck. I let games get away from me and lose their spark. I devote my prep time to the wrong things.

Granted, I do this stuff less now than I did 20 years ago, five years ago, or even one year ago — but I still do it!

I make mistakes as a GM. We all do. It’s okay to fuck up! That’s how we learn. It’s highly unlikely that anything hangs in the balance except a sliver of your pride — you won’t lose friends by making a GMing mistake, or bring about the apocalypse, or be forced to watch Sandra Bullock movies until you feel sufficiently bad about yourself. As long as you use your mistakes as learning opportunities, mistakes are great.

This article isn’t about that, but it’s still a point worth making. Here’s what it is about: A way to help avoid the problem of making particularly egregious, player-unfriendly mistakes — which is a problem, because as the GM you have the most power to make those kind of mistakes, and they tend to be un-fun for the entire table.

For example:

Writing an adventure that the PCs can’t complete without hiring other people to help them, and in which the helper NPCs get to do all the most interesting stuff (I did this once)

Not dialing back the toughness of a random monster battle in a “let the dice fall where they may” campaign, and killing a PC in the third session in a really boring, un-dramatic way (I did this, too)

Letting one player with a dominant personality ruin the game for everyone else at the table (I’ve done this at least twice)

Asking your players for extensive PC background material and then not using that material in the game (I’ve done this more than once, as well)

Those mistakes, while they were great learning opportunities for me as a GM, were also remarkably un-fun for my players — hell, in a couple of cases my mistake more or less single-handedly killed the game. And in hindsight, of course, it’s obvious that they’re mistakes. If I’d seen them written down beforehand, I’d have said, “Well duh, of course I’m not going to do that!”

But in the moment, in the thick of GMing, in the swirl of decisions and reactions and considerations and nervousness and excitement of actually running a game, things are less clear.

With that in mind, here’s a simple signpost you can erect in your brain — or better yet, paperclip to the inside of your GMing screen — to help guard against this class of un-fun mistakes:

When you’re about to make a GMing decision, ask yourself this question: If I were a player in this game, would I hate this decision?

If the answer is yes, pause, reconsider, and make a different decision — one that, were you a player in the game, you would appreciate.

If the answer is no, trust your instincts and make the decision you were planning to make. You might turn out to be wrong, but just by thinking about it you’ve helped reduce the chance of being wrong (and learned something in the process).

This isn’t a panacea, but it is one more tool in your GM’s toolkit of ways to be a better GM. It approaches the problem of making really bad, game-killing mistakes from a different angle — and angle that starts with the most important consideration in any game: Make it fun.

If you flip this question (“Would I hate this as a player?”) around, it looks pretty obvious: Don’t do things your players will hate. But read that way, it’s a lot less useful (at least to me).

I’ve never looked at things from precisely this perspective, and I’m of the opinion that the more angles from which you can consider GMing problems, the better — so hopefully this angle will be useful to you. It’s simple, easy to remember, and broadly applicable to a lot of different aspects of running a game.