[Can games be realistic emotional simulators? Game designer and writer Ernest Adams explores in depth how AI might actually emulate human emotions.]

Computers were first invented to crunch numbers for their own sake. Charles Babbage's Difference Engine was built to calculate polynomials, and Lady Lovelace wrote the first known program for his Analytical Engine to compute a sequence called the Bernoulli Numbers.

It wasn't until later that computers began to be used for applied tasks such as figuring out trajectories for artillery shells. Later still, computer games were invented. We put a veneer of meaning on top of a mathematical simulation to create an imaginary world, but often the veneer isn't very thick. It's particularly noticeable in economic simulations and role-playing games. You win the game by watching the numbers on the screen.

This makes sense in economic simulations, especially ones that are supposed to serve an educational purpose. Recently, I got a chance to play a beta version of a funky little game called Super Energy Apocalypse from Brain Juice Games. Its designer, Lars Doucet, characterizes it as "Sustainable energy use... AND ZOMBIES!"

Every night your community gets attacked by zombies (actually, garbage-eating aliens disguised as zombies... it's a long story). To win the game you have to develop non-polluting energy sources to power your defenses. Zombies love smog and nuclear waste, so you have to keep your eye on both the energy production rate and the amount of smog and waste you're creating in the process. It was fun, and, as it's based on real-world power generation systems, I learned some things.

For the most part, though, I'm starting to find myself a bit tired of games in which the mathematics are so close to the surface. I love role-playing games for the exploration, the stories, and their large variety of characters and locations, but I'm less enthused about the constant trading and upgrading.

All that emphasis on gear seems distinctly nerdy to me. There's not much difference between bragging about your Superior Glowing Voulge of Major Whacking, and bragging about your overclocked liquid-cooled Alienware PC with the Go-Faster LEDs in the case.

RPGs are about character growth, but it's all character growth as expressed in numerical terms. At the end of the game your character is faster, stronger, more dexterous, and so on; you have the figures to prove it. But he might as well be a robot as a human being. There's precious little of what we might call psychological character growth -- growth as a person.

So I'm starting to think about games that turn numbers into behavior. Of course, many games use finite state machines for their characters' AI, and the finite state machines take numerical values as input. ("If the enemy is within range, switch to attack mode.")

But these machines don't change -- the characters don't grow and learn to change their behavior. And as designer/professor Michael Mateas pointed out, finite state machines can't walk and chew gum at the same time -- i.e., they only exist in one state at a time, so they can't exhibit complicated mixtures of actions.

An early example of a "character" apparently changing its mood and behavior in a sophisticated way appeared in Chris Crawford's Balance of Power. I've written often about this game because it was both brilliant and unique -- a simulation of superpower geopolitical maneuvering that, so far as I know, has never been tried since.

It was a single-player game. You played either the USA or the USSR, and you tried to maximize your country's prestige at the expense of the other side, in part by facing them down in a series of diplomatic crises. (The Cuban Missile Crisis is the most famous real-world example.)

In each turn, both sides undertook various diplomatic activities (such as forming alliances) in smaller countries around the world, and in the next turn, each side had the chance to challenge the actions that the other side took -- a crisis. When a crisis erupted, one side or the other would eventually have to back down. It was essential to choose your battles carefully, because if you provoked the other side into nuclear war, you lost the game.

Balance of Power was such a hit that Crawford wrote a book explaining how it worked, right down to the equations he used. The book was called Balance of Power: International Politics as the Ultimate Global Game. It's long out of print, but Crawford has made a plain-text version available on his own website. I think it's a must-read for any game designer: a clear and intelligent explanation of how mathematical formulae turn into behavior.