King Monster Zones

King Monster Zones (Japanese: キングモンスターゾーン Kingu Monsutā Zōn, abbreviated モンスターゾーン in card text) are being treated as "King Monster Zones" by King Cards in which monsters Summoned from the  can be placed. These Monster Zones are introduced by Master Rule ROYAL, which will come into effect with the release of Kingship of the Duelist.

Any monster Special Summoned from the Extra Deck can be Summoned to a King Monster Zone. (See King Summoning)

Unlocking King Monster Zones
By activating a King Card, select any number of empty Main Monster Zones depending of that card's King Hierarchy, these Monster Zones are then treated as "King Monster Zones" where monsters can be summoned from the Extra Deck. This action is treated as "Unlocking" (Japanese: Kai jō) King Monster Zones.

Rulings

 * King Monster Zones can only be unlocked by King cards
 * The number of Unlockable King Monster Zones depends on a King card’s King Hierarchy (You can choose those zones).
 * A Main Monster Zone(s) must be empty before being used to Unlock a King Monster Zone. Occupied Monster Zones cannot be used.
 * When a monster Special Summoned from the Extra Deck leaves a King Monster Zone (by being destroyed, banished or sent back to the Extra Deck/Hand during your opponent's turn), that zone reverts to a Main Monster Zone, however you can still unlock King Monster Zones during your turn.
 * If treated as a Continuous or Field cards by its Spell Indicators, King cards can unlock King Monster Zones up to its King Hierarchy during your turns, while that card remains face-up in your field.
 * King can unlock King Monster Zones, even if a King Monster Zone has been reverted to a Main Monster Zone by a card effect during that same turn.
 * If a Link Monster’s Link Arrows point to a King Monster Zone, the latter still is treated as a King Monster Zone.
 * The 2 Extra Monster Zones cannot be used to Unlock King Monsters Zones.
 * If a Link Monster is Summoned to a King Monster Zone; you can Special Summon monsters from the Extra Deck, to Monster Zones its Link Arrows point to.
 * Even if King cards leave the Field, a King Monster Zone(s) remain unlocked for the rest of the turn, unless it's reverted to a Main Monster Zone by card effects.
 * Empty King Monster Zones are reverted to Main Monster Zones during your End Phase.

Card Text
The term "Unlocking" (Japanese: Kai jō) must be used in card's text when describing the act of treating a number of Main Monster Zones as King Monsters Zones upon the activation of a King Card.

For example, instead of "Once per turn, if this card treats up 2 Main Monster Zones as King Monster Zones: Special Summon 1 Extra Deck monster from your GY to 1 King Monster Zone", it should be "Once per turn, if this card Unlocks up to 2 King Monster Zones: Special Summon 1 Extra Deck monster from your GY to 1 King Monster Zone".

This is done in order to avoid excess of.