Unless specifically permitted, only a card's controller can interact with it in the following ways.
- Look at it (if it is face-down)
- Activate it (if it is a Set Spell or Trap Card)
- Activate its effects
- Tribute it
- Use it as a material for a Summon
- Have it conduct an attack
- Change its battle position
By default, cards remain under the control of their owners, but several cards can change control of monsters on the field, such as "Change of Heart" and "Creature Swap". When a monster switches control, it is placed in a Main Monster Zone on its new controller's side of the field (even if it was in an Extra Monster Zone). The new controller chooses which Main Monster Zone to place it in. Some monsters (such as "Mataza the Zapper" and "Blindly Loyal Goblin") cannot change control. Only monsters that are already on the field can change control; Special Summoning a monster that is in the opponent's possession to the player's field (such as due to the effect of "Conscription" or "Goyo Guardian") is not considered changing control of that monster.
If a monster becomes treated as an Equip Card, it is moved to the Spell & Trap Zone of the player whose effect caused it to be treated as one, and thus that player becomes its controller. For example, if "Relinquished" takes control of an opposing "Ryu-Kishin", it is placed in the Spell & Trap Card Zone of the controller of "Relinquished". Monsters that cannot change control cannot be equipped to monster in a way that would change their controller.