[daeken]

That's actually not true. A large part of the reason MMOs typically split the userbase into many shards is that the world design itself won't cope with the full userbase in a single instance of the world. You need a lot more space, a lot more places where interactions happen, etc. Imagine how much bigger the world of WoW would need to be to make the entire userbase work in a single world.

One of my favorite articles is on this very subject: http://www.gamasutra.com/view/news/114192/Opinion_Designing_...

[sp332]

I know. Deciding where to make the boundaries, and actually handling the handoffs between shards is difficult. It would be easier to write a game if you didn't have to worry about sharding.

[daeken]

I think you're misunderstanding what shards are. Shards in this context aren't pieces that interconnect, but rather completely independent worlds. A 'shard' is the entire world where players exist; players from shard A will never see players from shard B.

[sp332]

Oh, I've been referring to those as instances. Did I have the wrong term?

[daeken]

In the case of MMO architecture here are the relevant terms:

    - Shard: Encompasses all parts of a single game world
    - Zone: Area of the game which can't be further broken down; the players in this area are all connected to the same node and performing actions there.
    - Instance: Area of the game which is unique for a player or group of players.  This is done so that players can be together and not be interrupted by others, e.g. someone killing a boss before the group gets to it and having to wait for it to respawn.  These are created on demand by players and go away after the players leave.
    - Node: Single machine that runs parts of a shard.  This could be one zone with a high average player count, or a bunch of zones with fairly low player counts (e.g. large open areas) and maybe some instances thrown in.

Some details here can change from game to game, but most of it's pretty general.

[sp332]

Cool, thanks for the breakdown :)