Cards that can be put into the Battle Zone at the start of the game

Cards that can be put into the Battle Zone at the start of the game as the name suggests, are cards that can be put into the battle zone as you start a game.

Details
It refers to the following 4 cards.
 * Forbidden ~The Sealed X~
 * FORBIDDEN STAR ~World's Last Day~
 * Zerom, Origin of Destruction
 * Forbidden New Year

Rules
On December 12, 2019, the rules were revised to allow only one set of these cards in the battle zone. This is different from the usual process of entering the Hall of Fame and the Premium Hall of Fame, and is regulated by the General Game Rules, so it also applies to Hall of Fame Zero Duel.

The rule was enacted with the appearance of Zerom, Origin of Destruction, with several possible reasons why the rule was revised.


 * In a Hall of Fame Zero Duel, there was worry about the metagame environment of a deck with 4 copies of Zerom, Origin of Destruction and its Zeron Nebula.
 * In mirror match games, if both players were to use 4 copies of this card, 40 individual cards would be put into the battle zone at the start of each game.
 * At the start of a game, if "Forbidden ~The Sealed X~, FORBIDDEN STAR ~World's Last Day~, and Zerom, Origin of Destruction are each in the battle zone, it takes up a lot of physical tablespace.

Each of these cards is currently in the Hall of Fame, but due to this new ruling, they may be removed.