Yesterday I was talking with some friends and I mentioned in passing that video games like Age of Mythology (and RTS games in general) are more complicated than old games like chess. That seems pretty obvious on inspection but a lot of people resist it. Chess is a game for smart people while little kids play video games, right?
But consider how in chess you never have more than a couple hundred (or less?) moves to consider. You have 16 pieces. Some of them can't move. The pawns only have (at most) 2 options, the rooks only have 16 each, same for the bishops, and the king only has 4 options--all maximums unlikely to be achieved. The entire "space" of the board in chess can be represented with an 8x8 grits.
In contrast, even a very basic model of an RTS would require choosing several functions from an infinite dimensional vector space. Consider a simple model that says the winner is whoever the person who achieves a certain ratio of "active military score" where "active military score" is a function of your "aggressiveness" (a function you choose) and your "military score" which is a function of what units you have. The unit you have, of course, is a function of your economy and your economy (with say, three resources) is modeled as being a function of three "investment functions" you choose, one for each resource. Each of these functions you choose--the three investment ones, the military spending one, and the aggressiveness one are chosen from the space of all functions. Look at how much longer it takes to write even a very basic description of the game! And to teach someone chess might take 30 minutes, but to learn all the basics in Age of Mythology would take at least an hour.
Still, there is some truth to the fact that chess seems just as strategic. Even though the choices are much simpler in chess and the perfect strategy (one where you can't lose or would always win), if it exists, would be much easier to compute--chess has crossed a threshold where that perfect strategy still is impossible to compute. And thousands of books and billions of books haven't gotten the world particularly close to one. This, I think, illustrates a principle Stephen Wolfram talks about in his book A New Kind of Science. What he found was that even very simple computer simulations can exhibit very, very complex outputs. In fact, in technical terms, even very, very basic models can emulate ANY output of even the most advanced computer. (It's hard to put into words without using technical terms. Read more here.)
Chess is very simple. But it's complicated enough where it has crossed that threshold of complexity where its hard to tell complex systems apart.
The other factor is how both games are strategic. And in any strategic game, where its hard to predict what the other person is going to do, things get chaotic fast. This is the one sense RTSs might be simpler than chess. Chess, as far as I know, doesn't have that strictly defined of a meta-game. People can approach it with a lot of different strategies that can be hard to tell apart after just a few moves. In contrast, Age of Mythology has converged over the years toward one major meta-game, as far as I know, of rushing early and fighting it out by the end of the third age.
But even very, very simple games can become "complicated" because of their lack of a meta-game. Consider Texas hold 'em. If you don't bet on poker and just play the hands the game is completely deterministic--no one makes any choices. The strategic element comes from the choice that comes up a few times a game where you have four options: raise, check, fold, see. The sample space of choices is tiny. But because its so difficult to predict what others are going to do the game is "complicated."
Still, I don't think anyone who plays both games would argue that RTSs in general are harder to play. People make a lot more mistakes in RTSs. One mistake in chess can cost you the game--it's a big deal. In contrast, if you don't make a bad decision a minute in an RTS you need to get out more. It's more mentally exhausting to play Age of Mythology at any level than chess.