One person can be the GM; this is the person with full control over everything, and in whose account the campaign is stored. It is this account which determines the availability of such mentor-perks as dynamic lighting and such. Additional assistant-GMs can be set up on the main campaign page, by clicking the player's icon and giving them GM status. They can do (almost) everything the main GM can do, with a few exceptions (Such as deleting the campaign). -Phnord