Where variability comes from in a wargame

I've been thinking about where variability comes from in games, especially wargames.

Obviously, much of it comes from people, that is, from the opposition. And when there is more than one opponent, the variability becomes much less predictable. Some computer games try to reproduce some of this kind of variability, for example Civilization. In Civ IV the different "personalities" of the opponents are supposed to influence how they play.

It often appears to me that expert "Euro" game players are playing the players more than the system, though some of the more intricate mechanics mean the main point of effort is understanding and "controlling" the mechanic rather than understanding and "controlling" the people.

At any rate, here are some wargames and sources of variability:

Britannia--the combat system, that is, the dice rolls. In many of my Brit-like prototypes I'm trying to cut down on the randomness of the combat. Though 75% of the players think the amount of luck is OK, most others would like less luck. I laugh at people who say Brit is "too scripted", there seems to be great variation in what happens owing to both differing strategies and dice rolls. Freeform would make no sense in an historical game (note that Vinci and Risk, below, both freeform games, have NO element of history in them, absolutely none).

Vinci--the chit draws for the civilizations provide a random element. It is also very freeform. But mostly it is the people.

Risk--the combat system is the obvious variable, but even more, the territory cards and increasing reward for turning in sets; also there's the extremely freeform structure (you can go anywhere).

Diplomacy--there is occasional guessing in the tactics, but this game is almost entirely about people. Someday I may do a version of Dip stripped to its essentials, where there would be little or no tactical element, or perhaps a kind of a "Euro" version of Diplomacy (this might end up being two different games).

In most wargames, the dice rolling in combat is the main variable other than the people themselves. And that makes sense, combat is a very chancy business no matter how well-prepared you may be.

In many other games, especially those with little or no luck in the combat system, the Event Cards provide the variability. (E.g. Germania, Seas of Gold, Law & Chaos (yeah, that's not a wargame), etc.

Some games become "predictable" for lack of a random element other than the players--chess, checkers, Puerto Rico, etc. Yet when they are complex enough, there's still a lot of unpredictability. Checkers has been brute-force solved by computer, but that doesn't prevent people from playing.

I'm not sure where that gets us, but there it is.