Each Deck comes with 3 locations that should work well with the deck and give you an advantage. But don’t that that stop you from mixing and matching to find what works best for you.
There are two common ways to play Earth Tau. A Skirmish Deck is made of 20 Order cards (no more than 3 of any kind) and is used in a game with 1 location.
When you’re ready to step it up its time for a War. War decks are a total of 40 Order cards and will be fought over 3 total locations. Mix your Skirmish and War decks and get ready to rumble.