Feature: 'The Designer's Notebook: Numbers, Emotions, and Behavior'

Author: by Staff

Can games be realistic emotional simulators? In his feature article, game designer and writer Ernest Adams explores in depth how AI might actually emulate human emotions, using interactive drama Façade and Cold War geopolitical simulator Balance of Power. Citing an early but unlikely example of a video game "character" that changes its mood and behavior in a sophisticated way, Adams points to Chris Crawford's Balance of Power, a simulation of superpower geopolitical maneuvering released in 1985 for PC: "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." While specific characters didn't exist in Balance of Power, the actions of the AI opponent felt like the actions of a goverment. Crawford encouraged this feeling with the diplomatic language used to describe in-game activities. The language could be tougher of more conciliatory depending on how the other side was "feeling": "Crawford created a variable called pugnacity for each side, and another called nastiness which applied to the whole game. Pugnacity started at a slightly random neutral value (higher for the Russians than the Americans; this view is now rather outdated) and got higher or lower as its side engaged in aggressive or conciliatory behavior respectively. The overall nastiness of the game was increased by military activity and crises, and only went down with time. As Crawford says in the book, "The effect of these two terms is to create a mood to the game. Players who pursue confrontational strategies will increase their own pugnacity and the game's nastiness. Executed properly, such a ruthless strategy will encourage weak nations to Finlandize to the player. [note: in Crawford's parlance, "Finlandize" means to align themselves diplomatically with the player's country, a valuable achievement for the player.] But minor slips can cause the other superpower's pugnacity to increase and your own pugnacity to fall as you find yourself backing down too many times in crises." If you play the game often enough, you can actually feel this mood. Aggressive actions will cause the other side to become more hostile as well, but showing too little backbone will cause the smaller countries to think you're weak and align themselves with the other side. You can tell when you're not getting any respect." You can read the full feature, which goes more in-depth on how video game AI can emulate human emotions, pulling examples from titles like Façade and The Sims (no registration required, please feel free to link to this feature from other websites).