complex 3D environment. This is a lesson I apparently missed entirely, since I subse-
quently included companions inThe Suffering. Thankfully, my experience withThe
Sufferingwas much smoother, in part due to the lessons I had learned the first time
around. The other conclusion is that the amount of AI sophistication a game requires is
dependent on how much the failure of that AI will impact the player. If the AI screws up
and the player’s game ends as a result, that is very bad. If the AI makes mistakes and
the only consequence is that the player’s game gets slightly easier, then it is a failing
the players can probably live with, as long as it is a rare enough occurrence. So when a
designer is working on an AI system or critiquing a programmer’s work, he should
always keep in mind how important it is that the system function correctly. It is per-
fectly acceptable if only the development team knows of the AI’s stupidity while
players are completely ignorant of its shortcomings.
It would be nice to make every system in a game as smart as possible, but the reali-
ties of the production cycle dictate that there is only so much time that can be invested
in any given part of a game. Rare is the case that a programmer has finished all of the
work needed for a game and still has time to “polish” everything that he would like. As
such, spending a lot of time on overly sophisticated AI systems will directly take time
away from other tasks that desperately need work. The reader will notice that when I
listed the attributes that a game’s AI needs to have, I did not list “be a respectable, aca-
demic-quality artificial intelligence.” The AI for a game only needs to be good enough to
challenge players while not appearing overly foolish in its actions.
In his fascinating Game Developers Conference talk “Who Buried Paul?” Brian
Moriarty discussed the concept of “constellation” in games. This theory is of particular
relevance to game AI. Roughly stated, the theory is that humans, when presented with
some seemingly random data, will try to make sense of it, to put it into order, and to try
to find meaning where there may, in fact, be none. For game AI, then, Moriarty sug-
gested that having your AI perform seemingly random actions will cause players to
think the AI has some grand, intelligent plan. Players might think something along the
lines of the following: “Why did that platoon of tanks suddenly storm over that hill?
There does not seem to be any reason for it. Maybe they know something I do not.
Maybe they are regrouping with a force I cannot see.” Players who are not game devel-
opers themselves will have a tendency to try to believe that game AI agents make
intelligent choices. Of course, there is a fine line. If players see an AI agent pointlessly
ramming into a wall they will know something is amiss. It is important to remember
that players do not want to find bugs in your game, and will do their best to believe in
the intelligence of the characters they see therein. By throwing in some random behav-
ior, your AI agents may come out looking smarter than they really are.
Scripting...................................
Of course, game AI does not need to spontaneously think up every behavior that is per-
formed in the game. In some games, a combination of dynamic AI with predetermined
paths and scripted behaviors may create the most exciting experience possible for the
player. Usually scripted behaviors work best in games that have predefined locations
and where players are not likely to play through those levels repeatedly. In these
games, players are likely to come into a given area from a certain location, and therefore
168 Chapter 9: Artificial Intelligence