This format is kind of like 2 headed giant where their is 2 people on a team your starting life total is 30 you take your turn at the same time. A team shares a deck instead of having separate decks, share a graveyard, exile, and share a mana pool how ever their hands and fields are still separate. Since the deck is shared it should be a minimum of 100 cards.
1v1 Format
Each person will need 3 (or more if felt like as long as the deck number is agreed upon) 60 card decks constructed based on an agreed upon format.
Each person chooses a deck to start with and then plays a regular game with a start of 20 life, once one person has won that game they reshuffles all of their cards into their deck while the other player picks one of their other 2 decks, now life will be different from here on out with whoever lost the previous game getting 20 life but the other player gets a life based on their life total from the end of the previous game, ( 0 or less starts with 5, 1-5 gets +5 life, 6-10 gets +3 life, 11-15 gets +2 and 16-19 gets +1, 20+ would be left up to the people playing either 20 or whatever their life was). The games continue until one person has had all 3 decks defeated.
Each person will need 3 (or more if felt like as long as the deck number is agreed upon) 60 card decks constructed based on an agreed upon format.
Each person chooses a deck to start with and then plays a regular game with a start of 20 life, once one person has won that game they reshuffles all of their cards into their deck while the other player picks one of their other 2 decks, now life will be different from here on out with whoever lost the previous game getting 20 life but the other player gets a life based on their life total from the end of the previous game, ( 0 or less starts with 5, 1-5 gets +5 life, 6-10 gets +3 life, 11-15 gets +2 and 16-19 gets +1, 20+ would be left up to the people playing either 20 or whatever their life was). The games continue until one person has had all 3 decks defeated.