Games are interactive.
Most people think that means that the player does something and the game reacts. This isn't quite right: it's too narrow a definition.
Games have more in common with sports, work, and hanging out with friends than with movies, books, or spreadsheets. The first three are definitely, deeply interactive, whereas the last three are arguable.
See, a player doesn't have to interact with the game. Most games - and here I'm talking the whole scope of games, not just video games - most games are more about interacting with other players than with the game itself. Most games are simply structures that support an interesting way to govern interactions. They give players an excuse to be social together in specific ways, mixing up their normal social tendencies in a pleasant, structured, and relatively low-stress way.
A game's rules can be quite complex - roll the dice, choose three cards, if such and such then such and such. But in the end, the game's primary appeal usually boils down to the way it allows for interesting forms of socialization and its various cousins. This, of course, includes dominance play and so forth - not just simple socialization.
For example, poker isn't simply about percentages and potentials. It's about interpreting the body language and bids of the other players to determine how they fit into the percentages and potentials. It's about manipulating them into giving you the most cash.
Even the most unsocial games (like go or weiqi) are actually about socializing - about you reading your enemy's capabilities and aims, and seeking to counteract and accomplish.
Even single player games are about socializing!
Solitaire creates an imaginary second player: the deck. Using randomization, it attempts to simulate the actions and reactions of a human player. In Roulette, we use a bouncing ball.
Don't believe it?
Then why do so many gamblers think about the luck of the game as if it were human? Sure, they're not usually being serious when they think of "lady Luck", but they are being serious when they say that their luck has got to change, or that they are "hot".
We're hardwired to think of everything interactive as if it were at least marginally intelligent. Kids pretend (or flat-out believe) that stuffed animals are sentient. Adults treat their cars like they were people. We curse at the game when it gets too irritating, because that's what we'd do to a person who pulled this kind of stuff.
We're social animals.
We play social games.
The rules of your game aren't there to provide a specific level of challenge or whatever. The rules of your game are there to either provide a framework for people to socialize, or provide an imaginary person to socialize with. Someone who can be interesting and reliable.
As it turns out, providing a complex pattern to learn about and fun places to explore is an excellent way to provide enough of a social pattern to keep your players playing.
But when you think of every game as a dialogue, you'll be able to start telling what is "good" play and what is "bad". You'll be able to tell when play is "shallow", because you'll think to yourself, "our imaginary person is kind of getting off-topic." You can tell when play is "deep" because you can think to yourself, "wow, our imaginary person is insightful..."
And when it comes to connecting players to players?
That's a bit different. You're not creating an imaginary person: you're guiding real people.
Maybe I'll cover that some day.
Believe it or not, I really am working on a contiguous set of topics. All the recent posts about fundementals tie into this easily: the fundamentals are the "personality" of our imaginary person. The topics they like and the things they know most about.
Sorry it's so... scattered. I suppose I should write a book, but that's so tacky. Yah, because posting to your blog isn't tacky.
Anyhow, just some thoughts. Lemme know if you agree or not.