MA XIMUMPC MAY 200 5
HOW MMO WORKS
Every massively multiplayer online
game can be divided into two parts: the
server and the client. The client, which
you install on your computer, draws the
game world, sends your commands to
the server, obtains updated information
about the rest of the world from the
server, and then displays it. The server,
meanwhile, acts like an air traffic
controller for everyone in the game:
It monitors the status of each of the
players—where they are, what they’re
doing, what is being done to them,
and so on—and then makes sure that
all the other players are updated with
whatever information they need for
their game to progress.
The servers are the unsung heroes of
the MMO scene. Each game world—or
server, in common parlance—is actually
dozens of machines working in concert.
In addition to the zone servers that keep
track of player movement in the world,
there are chat servers that enable you
to communicate with other players, and
massive database servers that contain
everything the game server needs to
know about the world. Every signifi cant
game detail, including the gear your
character wears and carries, the skills
and spells he or she knows, the spots
where enemies spawn and the attacks
they can use, and even things like the
price that computer-controlled vendors
pay for a particular type of meat, is
stored in a database.
When you see a monster and decide
to attack it, the zone server fi rst notes
your movement; as soon as you press
the key to attack, the server shifts the
monster into attack mode. The zone
server looks up the attacks available to
that particular mob, and then executes
them based on the particular type of
creature’s AI. A shaman might try to cast
a spell on you, for instance, but a wolf
will just bite. This exchange continues
until either you or the enemy dies, or
you run away. If the enemy dies, the
zone server updates your character’s
record in the database server; when you
retrieve the loot from the mob, the bits
representing that loot are copied from
the creature’s database entry to your
character’s entry. Once that’s done, you
can move on to an encounter with the
next monster.
We’ve glossed over some of the
mundane details here; if you want the
real blow-by-blow, take a look at thesidebar “Five Ticks in the Matrix Online,”
on page 29.MMO MEANS BIG
PERSISTENT WORLDS
Persistence is one of the things that make
MMO games special. The game continues
whether you’re logged on and slaying
dragons or out in the real world washing
your dog. Players explore the game world
round the clock, and you can log on and
join them at any hour. While you play, day
turns to night, monsters roam the land,
and even the seasons change.
Maintaining this virtual world requires
the game servers to be online constantly
and the character data stored in the
game’s databases thoroughly protected.
If the character databases have problems
or lose data, the players lose the
time they invested in the game—and
that’s never a good thing. Most MMO
developers use a combination of fault-
tolerant RAID arrays and frequent, on-
the-fl y backups to ensure the integrity of
player data. Protecting the player’s data,
however, isn’t the MMO developer’s
biggest challenge: Creating the
staggering amount of content required tobuild a simulacrum of an entire world is a
far taller hurdle.
The typical single-player game might
include enough content for 40 to 50
hours of gameplay, but many people will
clock more than 1,000 hours per annum
playing their favorite MMO. In order
to deliver enough content to keep the
hordes amused, massively multiplayer
games must be gigantic. The landmass of
EverQuest , with all nine of its expansions,
covers more than 350 square miles:
That’s 15 times more acreage than all of
Manhattan!
And building the world is only the
fi rst step. Once the geography has been
established, it must be populated with
friendly non-player characters (NPCs) andTRIVIA: NONVIOLENT
MMO C HARACTERSIn games such as Second Life ,
A Tale in the Desert , and Star
Wars Galaxies , you can develop a
completely nonviolent character—
either a craftsman or an artist.EverQuest 2 is the best-looking MMO available today. The character models are
all bump-mapped and self-shadowing!M M O R P G
MM MM OO RR PP GG
M M O R P G
MASSIVELY MULTIPLAYER ONLINE ROLE PLAYING GAMESË