Welcome to Las Vegas
The Compact is a supernatural agreement unique to Las Vegas. It is signed by all of the major supernatural factions. It is effectively an addendum to the Unseelie Accords, including strict rules for allowed behaviors and proscribed punishments in Vegas. There is too much money and power flowing through Vegas to allow hostilities to sidrupt the bottom-line (but don’t make the mistake of thinking the factions are friends).
The Strip is Accorded Neutral Ground and any overt conflicts are met with draconian force.
The Ushers are an enigmatic group appointed by the factions to enforce the Compact (though all factions will get involved to deal with major infractions).