I want to put these ideas out for the Forge community to chew on. I first published them in EGG in 1990.  It is a way of analyzing games. I found it very helpful in game design work at that time. It moved me to always make rules as simple and straight forward as possible.

Be warned, there is a test at the bottom to see if you’ve read everything!

THE MACHINE MODEL OF GAMES
EXPERIMENTAL GAME GROUP NO. 9
first published 1990

(Summary of first part of the article: Imagine that a game is a machine – say a meat grinder. Information comes into it, gets ground up and the results of the game flow out of it. How can games be analyzed ?)

The Machine model looks at the problem points of games. Different game's problems arise from how they do information storage, info processing, and human interfacing. This, hopefully, will open the pretty colored boxes and stand all games up to the same "objective" test.

I see the following problem points: static, overload, friction, and waste.

STATIC: This problem creates confusion for players as to what information is stored, the process it is worked in and what they are suppose to do. Static comes from poorly written rules, and games that have not been adequately play tested.

Confusion is the norm in play testing. This is good since it points out the flaws of a game. This allows the game maker to correct them. If this does not happen though, the game fails to work since it can't transmit information if the players don't understand it. Much like shoving meat parts in the wrong hole and expecting bratwurst to come out.
The old adage "when in doubt read the instructions" comes to mind, but with static, the instructions don't help.

OVERLOAD: Researchers in the 1950s discovered that humans can store up to 7 "bits" of information in their mind at any one time. With a little education you learn how to combine ideas to seemingly increase this total (like learning the alphabet song, or an idiot savant memorizing the phone book) but the 7 bit limit remains. If you throw more information at a person than they can use, then it starts mounting up and overload sets in.
An overloaded player becomes even more slow at taking in new information, like doing the next turn, because they are still working on last turn. If they try to keep up, they do so by intentionally ignoring incoming information, and consequently not getting a complete picture of what is going on. They will blindly walk into an artillery barge. Finally, the player will become bored (since they are not really understanding or participating in what is going on). Boredom kills fun, and prevents problem solving.

The referee is often more at risk for overload than the players. If this happens then everyone suffers, since they can justifiable say, "you're just making it up as we go along!"
[NOTE: Remember this was 1990. My experience was that sharing out game master power, which is accepted now, was then seen as cheating.]

FRICTION: Overload causes friction. It is like trying to shove a whole cow into the grinder at once. The work slows down and undergoes a lot of stress. Friction also happens when the game's process of play is physically slow. For example, moving 5000 counters one inch every turn, or retrieving what the combat factor of the artillery is that is on the bottom of a stack of ten counters.

Friction often occurs when a game nears a critical moment. May times in play testing games breakdown due to internal inconsistencies, another good learning experience. But in a normal game, players want things to go smoothly. This means having clear simple events which tell a definite story.

Games filled with friction caused by unclear rules invite players to add their own friction in the form of bias, prejudice and rules lawyering. 

Most friction results from two sides meeting where one is not going to walk out of the encounter. One will win and neither will back down.

WASTE: Waste is the natural outcome of all of the above. If a game is like this then it is often a waste of my time. Time is an important commodity for me since I don't get to game all that much. It is also infuriating to have spent hours getting my men to battle only to have all the information I have been playing with be useless.

Boredom, slow game mechanisms, and an irrelevant smoke screen of information, waste my time since they do not give me what I want, a fun game.

[The article goes on to apply these four factors to the gaming experience of three different kinds of gamers.]

The Novice who is unskilled, isn't any good at mechanically playing the game.
The Experienced Gamer who is skilled at understanding games, and who is good at carrying out their actions.
The Experimenter who understands games but who wants something different.

Due to a lack of space I will limit this description to only one genre of game. I have chosen Role Play games because they are probably the most commercialized and least understood games out there. So let's see how this sucker works ...

THE NOVICE

STATIC: This is always a problem for novices. RPG’s are almost always filled with static but this does not matter too much since the player is not required to know too much about the rules. RPG character creation systems are usually well written and give enough for a novice to start play.
OVERLOAD: This too is a normal problem of novices. Again though, since most of the rules can be ignored and is not a big problem. A kind GM can even limit information to just what the player can take in and in so doing truly engage him in the game.
FRICTION: The critical points in most RPG’s are combat and magic. Many systems are relatively fast but friction is still a problem for many novices. I believe it is because man to man combat is imaginable that more players are not scared off from gaming.
WASTE: A well delivered simple RPG, is seldom a waste of a novice's time. They can do what is in front of them and by so doing be indoctrinated into game system thinking which "the experienced war gamer" is adept at.

EXPERIENCED WAR GAMER

STATIC: This is seldom a problem for most experienced gamers. Not only do they know the rules but many have figured out how unimportant most rules are. The unfortunate point of static of most old hands is that they become true believers of ONE set of rules. All other rules are branded heretical, and bias fills the air with clouds of self made static (hopefully not in the vicinity of novices - who have no idea what you are getting so worked up about!)
OVERLOAD: Many gamers learn the process of remembering vast quantities of numbers while playing games. This often leads them to believe that they have excellent memories. Well, I wish it were so, but it has more to do with having learned to cluster those numbers into big "bits" of information than anything else. Whenever the game requires players to keep track of players' information (player stats plus where you are plus the past damage on your armor plus the location on your body of fifty weapons, potions, etc. plus the exact activation words for each item etc.) It is common for old hand gamers to get overwhelmed in a "realistic" game.
FRICTION: Again, experienced gamers are not as plagued by this because of the learning they have about the game system. Really this is one of the reasons why I believe games are like machines. A gamers efficiency at playing a game increases with practice, the same thing happens when someone starts working on an assembly line.
WASTE: Experienced war gamers know what to expect when playing an RPG. In fact, the game is often secondary to just getting together with friends. There are others who really enjoy the mental activity of manipulating a bulky hard to play game. We all know rules lawyers and game- accountants.

EXPERIMENTER

STATIC: The price of becoming a rules maker is that the static of other games becomes painfully obvious. Unfortunately, most RPG’s are very unclear. They tend to center around character creation and combat. They all claim to be more "realistic," but their reason for that claim seems to come from having more tables and charts than the next guy. I find that RPG "rules" are mainly best ignored, least you begin to think they are serious.
OVERLOAD: Experimenters are open to overload a little faster than "old hands." This is by and large due to the experimenter’s tendency to dabble in many systems rather than specialize in one. In addition, experimenters tend to analyze games to death and come up with useless theories about them, like the machine model!
FRICTION: Once you begin to analyze games for their qualities, friction points become more obvious. RPG’s tend to break down when the players try to deal with the "big picture" of the world. This puts TOO much on the GM. If he is honest, he will cut the players off with a simple I don't know. Or maybe he is a story teller, who is willing to make it up as he goes along...but can he keep the story straight? This has more to do with the personality of the game master than the rules. Get a good group together and a good game follows.
WASTE: If a game brings up new ideas it is not a waste but it is too muddled to live then the experimenters time has been wasted.

[Now here is the test to see if you’ve actually read the article. I think my observations on role play games are absolutely wrong. I made these observations in 1990 from the perspective of a historical miniatures player. I was doing the early work on Engle Matrix Games and was not overly interested in RPG’s. I was pushing the idea that information could be better stored and manipulated by a matrix of words and arguments than by numbers. What I am interested here is discussing and applying the idea of games as machines and the problem points of Static, Overload, Friction and Waste.]

I found these ideas very helpful in game making because they made me look at the flow of information in a game and identify problems. It has led me to try and mold rules to what players seem to do naturally. So if players always take turns then I make the rule “Take turns”. If they talk at the same time then I give them a way to all get a say (because there is no greater static than everyone talking at once.)

My observations on different gamers’ experiences with the problem points is of limited use since I think RPG theory has moved well beyond them in 15 years. They are only useful to keep us in mind that different levels of experience yield very different gaming experiences for our players.

Chris Engle
Hamster Press = Engle Matrix Games

I really really like your Static/Overload/Friction/Waste set.  I also think you're right in discarding your characterizations of the three types of players.  But your four 'problem points' are pretty accurate in my experience, and (to my knowledge) not explicitly identified anywhere else.  These get at the key procedural issues of playing the game, and if we want our games to actually work at the table, we need to navigate all our talk about story and character and power dynamics through this meat grinder so that it actually happens.

You seem to say that Static and Overload are problems in and of themselves, while Friction and Waste arise from the other two; I'd disagree. I can see all four as distinct (but certainly related) issues.  Friction can arise without Overload -- and in fact, your example of the pertinent information being on the underside of a stack of counters is spot-on for that example.

Waste can also get a lot of use by defining it in terms in addition to time.  Wasted information, for instance: how much of the data you encode onto your character sheet is really and actually useful?  Do you really need to mark down every tally mark of health/xp/skill use/mana, or is there a better way to go about that?

These can be powerful tools to make the actual gameplay experience simpler, faster, slicker, and more fun.

I see what you mean about waste and friction. It could be a waste to write down a lot of information that is never used again. I hadn't thought of that.

My comments in game play styles was definitely all about "Rules? We don't need no stinking rules." Thank you for reading down to where I say I disagree with them now.

Chris Engle
Hamster Press = Engle Matrix Games

Definitely interesting. I'd agree with Joshua that the four phenomena are independent of each other. I'd also suggest that this analysis is at right angles to the Edwardsian idea of "points of contact" and that the two concept-sets illuminate each other:

the Glossary wrote: The steps of rules-consultation, either in the text or internally, per unit of established imaginary content. This is not the same as the long-standing debate between Rules-light and Rules-heavy systems; either low or high Points of Contact systems can rely on strict rules.

Wow, Sydney: yes.

To turn this a little more practical, we can implement these as design questions that we ask ourselves as we go: is this creating friction here?  Is it too much?  Is it clear?  Is it doing anything worthwhile?