Over in his LiveJournal, Mike Mearls recently set out what he calls Stross’s Law of RPG Design (after Charles Stross, inventor of the githyanki and other iconic D&D creatures):

A setting element should never require more than two paragraphs to explain it in full.

Assuming that “explain it in full” means “sum it up,” and not that those two paragraphs are the whole description, I like this concept. With that in mind, I’d like to propose a framework for applying Stross’s Law to setting elements in your game.

The way I see it, Stross’s Law (and Mike is influential enough in the RPG community that I’m going to go ahead and assume others will accept, and begin using, this term) isn’t just about efficient brevity, it’s also about staying on track. If it takes you more than two paragraphs to summarize a setting element, it’s likely to be too hard for your players to get a handle on right off the bat, and also to keep track of in play.

As a GM, you can spend hours and hours building elements of your game — by which point you know them backwards and forwards — but your players don’t have that luxury. Something that you know intimately is likely to be fresh to them, and also to be mixed in with a bunch of other equally new things. In other words, keep it simple and describe only the parts that matter most.

So if you want to put Stross’s Law into practice for the setting elements in your own game, what should you put into those two paragraphs?

I’m going to borrow a page from “The Seven-Sentence NPC,” an excellent article from Dragon #184 (which I wrote a bit about here on TT, in “Vibrant NPCs“), and suggest that your description cover these 8 areas — in one, or at most, two sentences each, and in this order:

  1. The most important thing about it (the core idea).
  2. What it looks like.
  3. How it fits into the setting.
  4. Why it matters in the setting.
  5. Something memorable or unique about it.
  6. Why player characters should care about it.
  7. Connections to other setting elements.
  8. Ways to use it in the game.

Will this work equally well for every possible kind of setting element — a massive city, a new race, an ancient artifact and a war between two kingdoms, let’s say? Probably not, as “setting element” is such a broad concept. But if you start out with this framework in mind, and think about each of these 8 areas, you should have a very good basis for writing a concise, useful explanation of any setting element in your game.

Edit: Charles Stross has now responded to Mike’s post, and Mike has written a longer explanation of his reasoning behind Stross’s Law. In it, Mike talks about reaching a “tipping point” where providing more details just serves to create additional work for the GM. He also makes an exception for things like the city of Waterdeep, in the Forgotten Realms (population: about 1,000,000), and for games where GMs aren’t encouraged to homebrew setting material.

My personal tipping point for detail in game information is probably higher than Mike’s — I’d rather have a bit too much detail, since throwing out or altering what I don’t like is less work than creating material from scratch (and more info = more ideas = more chances I’ll stumble across something marvelous). Since it sounds like Mike is saying that a setting element’s entire description should be two paragraphs long, I disagree with his approach to Stross’s Law (even though he wrote it!) — I prefer it as a guideline to creating concise, flavorful summaries.

What do you think?