My GMing Rules

These are the rules I have found useful in 45+ years of game mastering. They are not intended to be used dogmatically or pedantically. Judgment as always applies.

Basic GMing Rules

1: Garry’s First Rule of Fantasy
A) Do not change reality more than necessary to make your Universe work. Real world physics are your friend, you do not need to explain gravity, weather, or in general how the world functions. So don’t complicate things that do not require complication. Adding super science or magic is complication enough.
B) All role-playing games are fantasy, even if it is not. Of course it’s fantasy, if it was real you would be living it, not playing it in a game. Even the modern games or science fiction games are a fantasy.
"C) Fantasy is not an excuse for sloppy writing or world building. Never ever. "“Fantasy” is not an excuse word that means you don’t have to do your homework or keep track of things. Good fantasy is internally consistent. We do wish to write a good fantasy.

And we do want good writing. When I was talking with Melissa Scott at ConFusion and Her Friends (local SF convention) some years ago (2003) I mentioned running a D&D game for 27 years (at the time) Her eyes got as big as saucers and she said “That is writing too!” So you have it from a pro, and a well educated one. Your RPG writing is writing. Treat your game with respect, take writing it seriously and it will furnish you and your friends decades of enjoyment. Last note, just don’t take yourself seriously.

2: It is Your Game
It might be their system, but it is your game. At some point you have to say “we start here”. From here on end everything has to audition to get in. Just because Turkey Shit Rules or Lizards of the Coast wrote it is not a free pass. YOUR GAME. Even if you use a published setting. YOUR GAME. The next supplement for the World of Weeniecraft does not get a free pass, you need to approve it no matter how kewl Player X thinks the Hot Dog Cart of Doom is. YOUR GAME. If you want a good game you must take ownership.

3: Write to your audience
Know your players. Ask what they like and what they want to see in the game. Vital, ASK. Don’t assume, poll the players, inquire and check things out. Their role in the game is as important as yours.
On that note seek adventures of mutual enjoyment. If you are a sea adventure bunny (like me) and your players are not (like mine), then don’t write sea adventures. Write something you both like. You are part of your own audience. If you don’t like what you are doing it will show and enjoyment will be lessened.

Explore the limits, but be careful. Pushing the limits can be a good thing if you do not push then too far… Push people’s limits too far and they get uncomfortable. uncomfortable people are not having fun. People that are not having fun stop coming. Don’t even go there if you do not know your players very well indeed. It’s a game, not a psychological test.

4: The Rule of Yes
A) Unless there is a compelling reason to say no, say yes. Playing a game with Dr. No isn’t any fun. Players want to have fun and to do things. There is a time and place for obstacles, learn and know that time and place. Trying to find a royal blue shirt or spell components in the market is not that time.
B) A roll is not required for everything, even if a roll is required. Use judgment in applying the dice. Dice are random, random isn’t vital even if the rules say it is. Remember the Rule of Yes.

5: Keep encounters open ended
A) An encounter with one solution is bad. I do not write encounters with a solution in mind. I present the problem, and let the players tell me how it will be solved. Remember they are creative too. Use that.
B) Frustrated players are bad. Look back to the Rule of Yes. If your players cannot solve something because you wrote in a single solution they didn’t think of, they get frustrated. This makes the GM look bad.
C) Use any reasonable solution, be open to solutions you didn’t think of. As above, rule of yes and keep an open mind. You have one brain, your players have one each. Use the brains around you to improve the game.

A) Don’t script. Players will do the unpredictable. And that is that. You want north they go south. You have the old gypsy with the legend they visit everyone but. When that happens, punt. If an encounter is important, it can be fit in elsewhere. Only you know how the scenario is assembled. No one will smite you if you shuffle the parts. If the Vicar has the legend and not the Gypsy you don’t loose GMing points.

B) Let go. You are not in control, you were never in control and you will never be in control. The game is not about you the GM or your NPCs. The Player Characters are the Stars. Anything you do to derail that is bad, and anything you do to enhance it is good.

Most Important, have fun. The game is played for fun. If everyone is having fun, you are a successful GM.

© Garry Stahl: 2009. All rights reserved, re-print only with permission.


Excellent GM advice.

Thank you for sharing Garry.


Some really excellent advice three. Thank you!


Long time GM as well. Totally agree with everything.


This is great stuff. I think “It is your game” is particularly pertinent, given that there appears to be a trend of saying that the GM should never set boundaries. Setting boundaries is not the same thing as saying no to individual player actions. It’s a broader way of providing the right kind of constraints, which are necessary for any creative endeavor.


Robert Frost wrote “Good fences make good neighbors”. Boundaries are the fences of RPGs. Necessary.

One thing I do point out is yes, you can do anything you really want to, but actions will have consequences. If your PC kicks puppies, they will become known as a puppy kicker. Mothers pull children off the street, adult dogs growl and bark, merchants will not serve you, the Watch follows you around.

Still your actions are unlimited, as are the consequences.


Good rules, but saying yes too much can unbalance your game. Another good set of rules is what is found in the Hero System rulebook that is just 7 simple items that will improve any game.


I agree with the list; especially being flexible. If you don’t know your players, certain scenarios may not work out as you (or a publisher) intended. This why in my publications, I usually have sidebar to describing to the effect that the players may go a different direction and how to deal with it.


One of my GM rules of thumb is: the job of the GM is to enable the players do cool stuff.
It’s kind of a corollary to the ‘say yes’ and ‘write for the players’ rules; sure, there should be some challenge to the game - I’m not advocating letting them be a Mary Sue/Gary Sue/Munchkin - but the goal shouldn’t be to stymie the PCs (I hate riddle/puzzle scenes, from both sides of the screen).
Oh, and yeah, published background & setting material is ‘advisory’ when I run a campaign, kind of like a real-world history book is an incomplete and sometimes biased version of events. So, mostly true, but not necessarily complete.


This is a compelling post. So, what are the “just 10 simple items that will improve any game”?

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Well I was wrong on the number because it’s 7 things. It’s been awhile since I read Champions 4E. The following is an extract from there.


Re: number 2, Gary Gygax himself said as much way back in the first Dungeon Master’s Guide. He never insisted that people adopt the setting (such as it was way back then) or blindly adhere to the rules as written. So you could say that this has always been the spirit of, if not all TTRPGs, at least D&D.

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Yet he pontificated constantly in Dragon to play only by the rules, against house rules or unallowed classes or races. He is why every new class in Dragon was an “NPC class”, because Gygax would NOT allow any new player classes. AD&D was for “serious gaming”, what ever that is. Basic D&D for “the comic book stuff”.

So he was talking out both sides of his mouth. Having met the guy, I’m not shocked.

Things opened up a bit once he has been 86ed from TSR, but other things got very worse (in the business department.)

For third editon my classic example is the skills. Anything not a class skill is two skill points. This severely hampers anything not within the class boundaries. I wanted a Holmesian fighter, not possible, by the rules. So few skill points and everything but grunt skills hampered by the class rules. Pathfinder gives you a bonus for class skills, not a penalty for all the rest.

The vast majority of the tables I played and ran we didn’t use Dragon much at all. We tended to view it as optional material for what was in the books. Of which, both editions of AD&D stated that you need to house rule things because the rules do not cover every situation.

Thus the hierarchy of TSR publications was always:

  1. Core Rulebooks
  2. Splatbooks/Supplements
  3. Adventures
  4. Dragon/Gaming Magazines

That is just it, he pontificated, and few people listened. We played the game we wanted to. I still tell my players, “We will make your concept work”. However now I do not fight the rules, I fixed them.

I never said he got what he wanted, only that he wanted it. By the time he came down all rules only heavy that ship had sailed.

Yup, we were a lot more free thinking back then. It’s amazing how we went from You Can Try to If You Don’t Have X You Can’t Do Y systems of today. It’s like they intentionally removed all creativity from the players hands while at the same time telling DMs/GMs you’re not allowed to adjudicate because we don’t trust you.

That’s what I miss from the old days. The ability to think on your feet to overcome the situation without relying upon the numbers on the character sheet.

Classic example from my roleplaying, AD&D 2E was the game we were playing at the time. I had rolled up a swashbuckling bard just to act out an Erol Flynn fantasy. In the first adventure session the party assembles in a two story tavern that had prostitutes doing business on the second floor. My bard was Elvish and had a 19 DEX. He’s on the second floor overlooking the tables below where everyone is drinking at.

A fight breaks out between two npcs and the rest of the first level party is caught in the middle. My sister in law was playing a mage. She was cornered away from the rest of the group and couldn’t make it to them for protection. My character sees her in distress, so he decides that he’s going to hop onto the balcony railing then leap to the chandelier hanging in the center of the room. He was going to cut the rope when the chandelier was at its apex facing the mage in order to have it drop in front of her. My character would then be in position to stop her from being attacked. That was the plan anyway.

AD&D 2E didn’t have acrobatics as a NWP yet, so the DM tells me to roll my DEX to jump from the railing to the chandelier. I’m cocky because my character’s DEX is a 19. I have a 5% chance of failing the roll. I pick up the 1d20 and roll it…

I got a 20. A critical failure… my character plummets one story and lands face first on the tavern floor.

I’m thinking it’s not so bad since it’s only 1d6 worth of damage and I have 6 HP. Boy, I was wrong since the DM rolled a 6 for damage. The result was my character being knocked unconscious and proceeding to bleed out. We used the -10 HP is death optional rule.

Nobody in the party could get to my character in time. They were too busy fighting all the drunks which took 12 rounds. My character expired at ten rounds.

For those that didn’t play AD&D 2E, a round is 1 minute of time.

I use this story to highlight the differences between the old way of play and the new way.

Very well written, thank you for sharing!
Your Rule #1 is why I find the common framings and use of “Rule Zero” to be detrimental to the hobby. The spirit of Rule Zero is fine, ownership of your game, but it has become an excuse for arbitrary fiat with rules and setting which I feel is never a good thing.

The hallmark of the good GM is consistency. Yes once in a while you need to fiat, but you better fiat that way in the future. NOTHING pisses off players faster than inconsistent application. :face_with_raised_eyebrow: