Since all sets are considered "legal", the Standard format simply refers to a traditional 1 on 1 game. Original Card Wars rules apply.
This is a 2 versus 2 format, in which a player will sit directly across from his/her Teammate, with opponents to the left and right of the player. Two Landscapes will point toward each opponent. Each team has a shared total of 40 HP, and damage towards either player of a team will reduce this total. All other Standard rules apply.
This is an unofficial format, where there are 3 individual players all connected to each other with two Landscapes between each player. With 25 HP each, when a player is eliminated, the remaining 2 players converge Landscapes and proceed with Standard play.
Additionally, all cards OWNED by an eliminated player are removed from the game immediately (even if under another player's control.) Any "stolen" cards under an eliminated player's control are also removed from the game. Cards removed this way do not trigger Leaving Play effects.
Another fan-created format, Restricted encompasses all other formats and adds an unofficial banned/restricted list. With limited copies of certain cards, this format encourages the use of underappreciated cards.