online
Multi-state compact
Also: MSIGA, interstate poker, shared liquidity agreement
The agreement that lets regulated US states pool their online poker players: Nevada, New Jersey, Delaware and Michigan share tables through the Multi-State Internet Gaming Agreement, with Pennsylvania and others able to join. Without it each state is ring-fenced and fields are tiny.
Example. WSOP.com's Nevada, New Jersey and Michigan players sit at the same tables thanks to the multi-state compact.