[Rules for 2v2?]

Thanks but are those rules for Shadespire/Underworlds? 

I have a feeling that the rules I'm looking for are home-brewed....

[Rules for 2v2?]

Can anyone point me towards rules for multiplayer games with two teams of two players each (2v2)?

I recall seeing a mention of rules but can't find them now. One thing I remember was that teams could only have one copy of a given card between their two decks. 

Thanks!