From their site:
The new 2012 Steamroller document has been updated with additional scenarios and rules for playing in Steamroller tournaments. Event organizers need this document to organize their events, and players will want to familiarize themselves with the contents, including rules and expectations. Event organizers are encouraged to use any of the variants listed in the appendix to make each Steamroller Tournament unique and enjoyable to players.
Steamroller 2012 PDF