The world of Ultima Online is divided up into many partitions. To show the enormous amount of processing required for Ultima, observe the following.

When you begin the game, you are put in a singular world. In that enormous world, there are six servers that comprise the world, which meet each other at "server lines" to attempt to create a fluent world. There is also a seventh server known as "The Lost Lands" available for UO.

In addition, each shard of Ultima has two worlds, Felucca and Trammel. Trammel is the new shard of each server, where playerkilling is outlawed unless members of opposing guilds agree to combat. The rules for pushing people out of the way do not apply in Trammel, and you can go running through miles of people without losing a single point of stamina.