I figure they must be some soft of trigger or sp but I cant find them.
Attribute Rules are stored in the GDB_Items system table. Specifically, within the definition column of the feature class that the Attribute Rule is applied to.
Geodatabase system tables in SQL Server - Tables that implement enterprise geodatabase functionality
FAQ: How do I query the DEFINITION column of the GDB_Items table in a SDE geodatabase?
So do I need to have all connections to my database terminated in order to add an attribute rule? I have a lot of layers to transfer rules to. If not it seems odd that I can't do this while other connections are active.