According to the Lumpley principle, System is that which exists at the social contract level by which participants decide what is happening in the shared imaginary space. As such, it encompasses just about everything that we call game play.

However, in at least two threads recently, I've seen system used in at least two distinct ways that appear to be different from this.

In Does anyone else distinguish between System and Mechanics, Jeff was trying to define system as that which is in the book that is not mechanics. Now, to my way of thinking, as much of the system as is in the book is mechanics, even if I'll agree with Lumpley that there's another layer to the system that is social contract--but as against Jeff, I don't think that can ever really be in the book.

Similarly, someone buried somewhere in Aesthetics and Conveying Reality distinguished system from color and other areas of exploration. I'm more comfortable with this, but if I apply the Lumpley principle strictly, color is certainly one of the factors by which participants decide what's happening in the imaginary space, and therefore part of system.

That tells me that the word system has fallen into that very dangerous category of words that we all use to mean something different.

Apart from the Lumpley principle, I would use it to mean the totality of a game as it appears in the core books, including any mechanics and setting information that create the experience the game wishes to convey. I don't pretend that this is the only possible definition; but I think if we're going to continue to use the word, we'd better recognize that we've got different definitions and come to some understanding of how it's being used in any specific context.

--M. J. Young

M. J. Young wrote: That tells me that the word system has fallen into that very dangerous category of words that we all use to mean something different.

Apart from the Lumpley principle, I would use it to mean the totality of a game as it appears in the core books, including any mechanics and setting information that create the experience the game wishes to convey. I don't pretend that this is the only possible definition; but I think if we're going to continue to use the word, we'd better recognize that we've got different definitions and come to some understanding of how it's being used in any specific context.

I agree that it makes sense to distinguish the system presented by the game text from the system manifest in actual play.

Best Case: when you have a) coherent, complete, fully instructive rules in the game text, plus b) players playing strictly by those rules, the two senses of system are practically identical. That is, the actual play system lines up nicely with the system presented by the game text. That's what we as game designers want and work toward. (We can't control b) at all, of course.)

Less Good Case: if you don't have both a) and b), the system in actual play diverges from the system in the game text. That's okay; even if we as game designers would rather it didn't, that's what happens. The important thing is: there is still a system in play. Otherwise consensus would break down and the game would come to a crashing halt.

Now, this thing I'm talking about, this system-in-actual-play? It doesn't matter to me what we call it. Ron called it System, and that makes sense to me, but whatever. We gotta call it something, and we gotta recognize that whatever we call it, the rules and mechanics in the game text aren't reliably it.

(Now, realize that the reason I care about this is that I want to write Best Case games. Same as we all do. I'm not just harping on the limitations of mechanics; I'm saying that if we want people to play our games the way we intend, we have to be clear and precise when we tell them how.)

-Vincent