The Unconstrained GM

Imagine being able to GM on the fly with no books by your side, no prep notes, no monster manuals with pages bookmarked, and no laptop and increasingly essential (no pun intended) D&D Insider account acting as persistent distraction at the gaming table.

Imagine being able to run a successful Fourth Edition D&D session using nothing more than a single sheet of paper.

That’s how I game, and today I’m going to show you how.

The key, really, is boiling 4e down to basic numbers. A GM screen goes part of the way but tends to scatter the different level-appropriate values all over the place. I made my own one-sheet summary a while back, then shifted to using Sly Flourish’s excellent Master DM Sheet for a while as it was far superior to my own in every way.

Time passes, and I have created a fresh sheet which simplifies things further.

Here are the first three levels.

Average AC & to hit AC = Level+5
Average Defences & to hit Def = Level+3

That’s all of Fourth Edition D&D from a DM’s perspective from 1st to 3rd level, in a nutshell. Here’s the full thing from 1st to 30th level.

The columns marked Low, Medium and High show three different values each. The first is the Difficulty Class (DC) of any given skill or attribute check at that level. A High (ie, Hard) DC check at Level 3 is DC21, for example.

The next value is the damage. In general, use the Low column for attacks which affect multiple foes, the Medium for the majority of attacks and the High column for powerful or special attacks which can only be used a limited number of times per encounter. The value in brackets in the Medium column (where it says 1d6+4 (5) at 1st level, for example) gives the damage value for Minions. I also use that value for Ongoing Damage as well, to keep that scaling up the levels neatly.

The High column shows no dice notation as High damage always uses the same number and type of dice as Medium damage. There’s two numbers separated by a slash; the first is for a regular High damage attack, and the latter for a Limited High Damage attack.

I could (on the fly, right now) invent a Purple Dragonnette at Level 3. Its Bite Attack does 1d8+6 damage and Tail Swipe does 1d8+10 (High damage, Limited) and Slides opponents 1 square against opponents foolish enough to get behind it. The breath weapon is a cloud of noxious purple fumes that does 1d6+5 damage as a Close Blast 3.

The last part of the High/Medium/Low columns show the Hit Points, depending on whether you want this particular monster to be tougher (in 4e-speak, a Brute) or weaker (a Lurker, for example) than the level would represent. The Purple Dragonnette above might have High Hit Points  (58) as a 3rd Level critter while a cowardly Blue Orc (also 3rd Level) might have Low Hit Points (36) to reflect his eagerness to lay on the floor and play dead until the nasty heroes go away.

The final column shows the XP value of a Monster or Trap at that level, with the number after the slash giving the XP value for Minions. The note at the bottom of the table shows how to calculate AC, Defences and to-hit values. The Purple Dragonnette would have AC 18 and other Defences 16. The Bite Attack is AC at +8, Tail Attack vs Ref and Breath Attack vs Fort at +6.

Note that all of these are just average values – if you want a monster to be particularly agile for example, adjust Reflex Defence up by +2 and lower one of the others by –2 if you want to balance things out. They’re the products of your imagination, so use the numbers as a guide and adjust to taste.

Add other effects of damage to keep that 4e feel. Use Push, Pull and Slide to keep the game mobile, and use conditions for particularly nasty attacks. The Purple Dragonnette’s breath attack could leave the victim in a coughing spasm (grants Combat Advantage (save ends)), or whatever effect your whimsy takes (turns them into pretty butterflies (Unable to attack or move other than Shift 1 (save ends)).

The thing is that this can all be done in-play. Put a ruler underneath the line equal to the party level (raise or lower it if you want high or lower level foes for this encounter) and just pick the numbers for the creatures and traps as you go. I jot down minimal notes about the creatures for later reference such as “Purple Dragonnette 3, HP 58, AC 18/16, Bite M +8,Tail HL&Slide1 +6R, Purple Cloud CB 3 L +6F”. Not just easy – old school easy!

The same table can be used for Traps. A column of flame which shoots upward when a pressure plate is pressed could be a Level 2 Trap doing 1d8+5 damage + 5 Ongoing (save ends), +5 vs Reflex. Use the DCs for any skill checks (jumping across a Flaming Pit, or scaling a Gelatinous Wall) and the damage results for any consequences of failure.

If you’re letting the players roll all the dice just give them the appropriate DC for the attack (10+Level+5 for AC, or 10+Level+3 for any other Defence, modified by whimsy) and the damage value. You can focus on telling the story while they roll the bones.

What this does is take the game back into the unknown.

You are no longer using familiar foes from the Monster Manual, but creatures which the players (and therefore the heroes, by association) have never previously encountered. That short green ugly humanoid might well be a Goblin, but he won’t be like any Goblin they know. This one could be a Feyrie Goblin, a Level 1 creature that can become Invisible until the end of its next turn when it hits with its Unsee-Me Stick (Medium damage, +6vsAC). Or a Moss Goblin that infects its foes with Moss Rot with a touch (Level 1 Minion, +6vs Fort, 5 Ongoing Damage. On death, victim turns into a small mound of moss-covered topsoil). Or any one of a thousand other unknown creatures from your mind.

If you use just this one sheet and pass the dice over to the other side of the table, you’re free to focus on the story. There’s no jumping between rule books or flipping from one Monster Manual to the next. All of the numbers you really need are right there in front of you all the time. The part of your brain which usually focuses on finding the right page or worrying about the next encounter can instead come up with cool details, plot twists or throw itself into characterization. That’s a good thing, right?

And all that prep time –  gone. Spending four hours to prepare a two hour session is a thing of the past. Dream up a starting point for the scenario on the way over, and use the extra free time you’ve gained in-game to dream some more. Zero prep role-playing is the art at its finest, true collaborative story-telling with no rail-roading at all. Heck, there’s no rails to road.

If you’re the kind of GM who loves the comfort blanket of preparation, it takes a massive leap of faith to give it a try, but I heartily recommend it. It’s a step into the unknown.

Welcome to the ways of the unconstrained GM. You’re a part of the club now.