From experiance mostly. We set up a private FFXI(Final Fantasy Eleven) server. We were able to fake a server rather easily though the content needed to remade. For the most part all the maps were present, some clipping issues on some maps and a couple you would just fall through. None of the maps had and mobs or NPCs. We had to link the models and pathing AI for each mob we wanted to spawn. We have to recreate our stats and link all the items with the correct animations and effects for abilities. None of the mobs had stats or HP or loot tables. We had to link all the animations for their moves and abilities, we had to gather a lot of theorycrafting from various fan sites to build what we think was the actual stats of the mobs. After a while we had spawning mobs that had pathing and aggro ranges and loot tables that we had to make. Then the NPCs we were able to spawn and we only had to link the correct dialog to the right ncp and luckily the triggers for quests were linked with the dialog chain. The shops were not though. We just linked every shop to the same NPC so we could save time. Also had to set the prices. The missions themselve were about as hard as the NPCs to make. Once we found the triggers to start them we just had to add the location trigger for the event to start. The dialog would continue at appropriate points, though we had to make the bosses and adds spawn or the mission would continue as if we had beaten them. Mission rewards were not there, we had to add them to the loot tables. Also had to link any teleportation to the correct places if the mission were to transport you or it would bugg out. One odd thing was the NM's(rare monster spawns) the timers and locations of their spawns worked fine, we just had to link the right mob to spawn. Their loot tales had to be remade like the others though. All in all it was a decent facimile though, it was nothing close to the actual experience. A great deal of information is received from the servers. Without them, or a great deal of Jurrasic Parking some Code, your disc is worthless. Key components for the content are loaded from the servers to keep people from doing just what we did. That is what I am basing my arguments on.