The NHL issued a three-page document with bylaws to the Expansion Draft but it was a rule instituted by Vegas Golden Knights GM George McPhee which had dramatic and surprising impact.
McPhee and assistant GM Kelly McCrimmon believed from the onset of their expansion quest that the other 30 NHL teams could prevent Vegas from achieving its goals by trading amongst themselves.
A "massive redistribution of talent," was how McPhee described the wrinkle he worried most about when making his plans. The Golden Knights hockey operations staff decided they needed to get in front of such a possibility. To clog the market and make sure they controlled the process.
They got on the phone early and let GMs around the NHL know they were open to deals.
The caveat, however, was once a team had agreed to a deal, Vegas told them they couldn't make other trades which would affect the expansion draft.
McPhee and McCrimmon worked to close their deals and once an agreement was set - they informed their trade partner of the condition attached to the agreement.
Deal with Vegas and no one else was the arrangement. And it took hold and deflated the market.
It was a stroke of genius by McPhee and McCrimmon.
Vegas took the offensive and clogged up trade traffic.