To the players it is fun and games, but there's a great deal of very complex "behind-the-scenes" technology at work in today's global online gaming environment.
The network architecture for online gaming is growing increasingly sophisticated as the genre evolves.
Industry observers note that in just a few decades, games have moved light-years away from gobbling pacmans and primitive graphics.
Today, they say, games like Everquest and Ultima employ artificial intelligence and complex client-server systems to enable their millions of subscribers to role-play in massively multiplayer online (MMO) environments.
A unique feature of MMO games is that they are "persistent" -- the fantasy gaming world is always available, and the plots and events continue to develop even while players are not playing their characters.
Games have already influenced the way movies and advertisements are designed, and experts speculate they may play a future role in the way online networks are architected.
"People are looking at successful MMOs and realizing there are strengths that apply to more than just role-playing games," says Aaron Cohen, producer of Ultima Online at Electronic Arts, a major gaming company based in Redwood City, California. "MMOs are really good at building communities, and that's becoming more and more important."
To manage hundreds of thousands of subscribers while also delivering a consistent experience, MMO games are typically sub-divided into groups of 10,000 subscriptions assigned to a dedicated server. These will typically have about 2,000 -- 4,000 active players at any given time.
Each server corresponds with a "world", or a slightly different version of the game. A world might be compared to a television show where the audience participates according to the rules set for the characters they choose to play.
"Worlds and games are not the same thing. Think of worlds as alternate realities. They are reflections of each other but a little different because different people play in them," says Cohen. "The game is what players bring to [the world]."
The servers for each world handle a variety of functions. "We do keep a lot of stuff on the server side so people can't cheat. They can't edit their characters to give them more extraordinary powers," says Cohen. The server keeps a big record of all the player's statistics: it tracks where the player is moving, what he's doing, and how he does it.
Role-playing MMO games also include an element of chance, and hence, artificial intelligence (AI) is used to manage the possibilities.
The server rolls the dice, so if players are fighting a dragon, it needs to track the part of the dungeon the players and his friends are in, and records each hit they make on the dragon. In archaic games, when a player hits, the same amount of damage is done each time to the adversary. Not so with MMO games.
"There's one roll that says whether you can hit or not, and the computations may include the dragon's armor dexterity, how fast you are, and all manner of computations that go into a rather long equation," says Cohen. "So the server computes the damage, and then it has to work the monster's AI: does it run away, chase, or attack."
Compared with a banking system, these gaming transactions are more complex. "There are no randomizations -- the bank's server is not going into someone's checking account and doing a dice roll to see how much money is in there," he says. But banks handle a far greater volume of transactions than MMO games. "The biggest MMOs deal with a couple of million and that's miniscule compared with a bank."
Gordon Walton, an independent gaming consultant based in Austin, Texas, says the real-time applications used in gaming are unique. The closest application in the business world would be an airline reservation system, he says. "[Gaming] applications have to be real-time, squared," he says. "There's hundreds of thousands of players running around in worlds, doing things that cause database transactions, in real time. You can't batch them and run them at midnight, because the player may be using the thing he just did the transaction on three seconds later. So this is a high-performance application problem."
Security for MMO games is on par with industry standards, he says. "Even though the stuff in the game isn't money, the same security issues crop up. Players would love to break into our computers and give themselves the invincible sword of whatever."
However, notwithstanding the huge numbers of youthful, tech-savvy players MMO games have to contend with, security features have held them at bay thus far.
"Players pound on our servers quite a bit," says Cohen, but points out that security for an older game like UO, which has been around for eight years, has yet to be cracked.