Attack declaration window

The Attack declaration window is an unofficial term for the activation timing of cards that respond to an Attack declaration, such as "Sakuretsu Armor", "Mirror Force", "Magic Cylinder", etc

The Attack declaration window will only open if a monster is declaring an Attack by the game mechanics during the Battle Step.

During the Attack declaration window, due to Fast Effect Timing, first the turn player must activate any compulsory effects that they triggered, such as "Evigishki Levianima", then their opponent must do the same (if they has face-up "Ordeal of a Traveler" for example). Then, the turn player has the opportunity to activate optional effects like "Ego Boost"; if the turn player passes, then the opponent also has the opportunity to activate these effects. If at any point either player starts a Chain, standard Chain rules are followed. However, if this Chain resolves or neither player respond to the Attack declaration with their cards, then the attack declaration window is closed, and neither player can activate any of the previous cards again until the next Attack declaration.