Extra Monster Zone

Extra Monster Zone
Japanese	EX（エクストラ）モンスターゾーン
Japanese (ruby)	エクストラモンスターゾーン
Japanese (base text)	EXモンスターゾーン
Japanese (romanized)	Ekusutora Monsutā Zōn
Japanese (translated)	Extra Monster Zone

Extra Monster Zones (エクストラモンスターゾーン Ekusutora Monsutā Zōn, abbreviated EX（エクストラ）モンスターゾーン in card text) are the 2 Monster Zones in the center of the field in which monsters Summoned from the Extra Deck are placed on the field. These Monster Zones were introduced to the OCG in Master Rule 4; they do not currently exist in the TCG.

As per Master Rule 4, if a monster is Special Summoned from the Extra Deck, it must be placed in either the Extra Monster Zone or a Linked Zone. If a monster is Special Summoned from another location, even if it is an Extra Deck monster, it is Summoned in a Main Monster Zone. If control of a monster in an Extra Monster Zone is changed, it is placed in a Main Monster Zone, even when returning control to its owner. If a monster in an Extra Monster Zone is temporarily banished, when it returns to the field it is placed in a Main Monster Zone.

While an Extra Monster Zone is unoccupied, it is not treated as being part of either player's field. While a player controls a monster in an Extra Monster Zone, that Zone is considered to be part of that player's field. If a player already controls a monster in one Extra Monster Zone, they cannot Summon a monster in the other Extra Monster Zone unless there is an Extra Link to the other Extra Monster Zone.

However, even if the opponent controls both Extra Monster Zones due to an Extra Link, this does not prevent the player from Special Summoning to an Extra Monster Zone by using a monster in one of the Extra Monster Zones as Material (e.g. Special Summoning "Chimeratech Fortress Dragon" using an opponent's Machine-Type Link Monster in the Extra Monster Zone as a Fusion Material).