So every once in a while we talk about two broad-based philosophies of game design, that being (a) designing for what matters in your game, and (b) designing away what doesn't matter in your game. So if you wanted to design a game for, I dunnno, clan-based politics, following the Design What Matters method would provide mechanical support for players manipulating relationships with others, forwarding their beliefs, convincing others, maybe blackmail and skullduggery, that sort of thing. Following the Design What Doesn't Matter method you provide mechanical support for combat, buying things, travel times, and maybe some wilderness encounters. Assuming that the players know what the game is supposed to be about (which is a different matter entirely), two groups using the two games will end up playing something roughly similar in content. If the end result is the same, what's the big deal? You have to go into a little more detail to find out.
"Okay, you want this? Here's some tools to do that."
Design What Matters says, "Okay, you want this? Here's some tools to do that." It provides explicit and relatively exacting instructions on how to pick and hit that target. These designs are usually highly idiosyncratic, focused, and balanced. As such, they are either resistent to kit-bashing and house ruling or fall apart when subjected to such treatment. Someone once called them "Designer Games" which is pretty accurate, not in the sense of designer jeans, but in the sense of designer drugs. They're built for a finely-sharpened purpose. Typically speaking, they don't do anything else, or they do it poorly. These games are tools that allow you how to do something that you may have never done before.
For a nearly exhaustive distillation of Design What Matters, see The Power 19, which is all about identifying what you're designing for and then figuring out how to design for it.
Examples of Design What Matters: Primetime Adventures. Dogs in the Vineyard. Once Upon a Time. Monopoly. Scrabble. A forklift. A pulley.
"Okay, you want that? Let me get rid of all this other stuff for you, so you can focus on that."
Design What Doesn't Matter says, "Okay, you want this? Let me get rid of all that other stuff for you, so you can focus on what you want." It provides vague or even non-existent instructions on how to focus on anything; in fact these games shy away from focus as a general concept. Instead, this philosophy provides many and varied methods to not focus on things, to resolve them quickly and move on, to avoid depth and complexity. The goal is not to provide the most superficial experience possible; it's to marginalize those skipped-over elements so that you can focus on the "real meat" of roleplaying, whatever your group happens to think that is. That's also an important part of this philosophy -- it assumes you have a functional or semi-functional group who is able to decide what they want and do the focusing work themselves. Which is, really, something that any group of adults should be able to do if they know each other marginally well. Because of this philosophy, these games can "do anything" because the game doesn't actually do it; the players do. The game just removes all the other pesky details that are getting in between you and your fun. It's a tool that helps you do what you would already be doing, and do it better. It is, at root, a labor-saving device.
Examples of Design What Doesn't Matter: GURPS. Shadowrun. World of Darkness. Blue Rose. Mind's Eye Theater. Costumes. MacOS X. Microwave ovens.
In the end, they're all just tools, albeit with different uses, at your disposal. You use the first set of tools to build what you want, you use the second set of tools to clear away the stuff you don't and build what you want on your own. Still sound like no big difference? Let's rephrase it in terms of the range of use of those tools.
Design What Matters games let you play anything the tools allow you to build.
Design What Doesn't Matter games make it easier to play anything that you could have come up with on your own.
Ah ha, now we're starting to uncover the difference. The two philosophies, in addition to functioning differently, also provide a different range of possibilities. I'm not going to go into which philosophy has a broader range here; in fact I think that's probably an effort in futility, and generalized observations will be trumped by specific reality every time. The important thing to realize is that there are some things that the tools can build that are beyond your ability to do on your own, and there are some things that you can do on your own that the specialized tools can't do. Because I like rephrasing, let's do it again!
Design What Matters pushes you beyond your normal limits.
Design What Doesn't Matter makes you comfortable within your limits.
It probably sounds like I'm saying that the first is better than the second, doesn't it? Being comfortable is for pansies, we should always strive to push beyond our limits all the time, 24/7, rah rah rah, right? I don't know about you, but when I'm coming home from my two-hour commute through the heart of Los Angeles, my limits would really appreciate not being pushed right about then, and it'd be real nice to get comfortable in some pajamas, a blanket (it's cold recently), and maybe a cat or two. So too, sometimes it's just nice to settle into a well-loved character, setting, or game and just get comfy in that milleu. Just look at games like Munchkin and Hackmaster for examples of how that comfortable-in-the-game phenomenon can be sold nearly undiluted (albiet with a postmodern self-referential spin, as always).
Or perhaps we can ditch the whole pansy-sounding 'comfortable' thing and say that Design What Doesn't Matter enhances what you've already got. Or that it liberates you to focus how you like -- it's like gaming feng shui (the philosophy, not the ninja game). Design What Doesn't Matter is sort of an optimization of make-believe, and that's pretty cool.
On the Design What Matters side, we can start to see this as more of a challenge, a dialogue, or a prod -- the goal is to move your frame of reference beyond the prior limits of your experience and ability. While it can be "softened," this sort of thing is by its very nature not comfortable. Or it is "comfortable" in the same way that an endorphin burn or adrenaline rush is comfortable -- the correct word here is "euphoric." I doubt many people are comfortable playing Dogs in the Vineyard, but I'm sure most folks certainly experience euphoria somewhere in the process. We've come back to the designer drugs analogy -- Design What Matters games try to provoke a specific altered state of consciousness, one that may be beyond your normal experience.
Again -- and I hate to have to jump up and down and keep repeating this, but I feel it's necessary -- I'm not saying that one is fundamentally better than the other by any means. What I am saying, however, is that these two philosophies lead to two design approaches which result in two different kinds of play. The results are different. Sure, the content is the same -- you can shoot people in the face in Shadowrun or in Dogs -- but the difference is in the experience. Shooting people means something different, feels different, works different; it has a different weight and tone and quality. All of that comes from how the design impacts play -- which is why design philosophy is so important.
I, personally, am going to keep writing Design What Matters games. I doubt that's a surprise. The reason why, however? Cause the Design What Doesn't Matter market's already swamped, and I'm not interested in wading into that kind of competition. Thanks to GURPS and OGL, there very literally is not one genre or premise that I can think of that doesn't already have a supplement that can be used to run it, and there are more coming out every day. Especially in the case of GURPS, the stuff that's already out there is superior to what I could produce. So when I want that kind of experience -- the feng-shuied tricked-out optimized and streamlined facilitation of my own imagination -- I'll go there. The stuff that needs writing -- the stuff that pushes me into new experiences and revelations about myself -- that's where I'll be in the mean time.