Can I play a spell on the opponent's turn?

Yes, you can play a spell on your opponent's turn, but only under specific circumstances defined by the rules. You cannot simply play an Action spell at any time during their turn; it must be a Reaction spell or a specific game situation that grants you permission.

Here are the conditions under which you can play a spell on your opponent's turn:

1. You can play a [Reaction] spell

If your opponent plays a card or activates an ability that uses the chain (creating a "Closed State"), you may play any spell with the [Reaction] keyword.

• Why: According to Rule 309.1.a, only cards and abilities with the [Reaction] keyword can be played during a Closed State.
• How: This adds your spell to the chain. The chain resolves in Last-In, First-Out (LIFO) order, meaning your reaction will resolve before the opponent's original action.

2. You can play during a Showdown

If a Showdown occurs (usually when a unit moves to a battlefield), you have an opportunity to play spells, even if it is not your turn.

• If the chain is empty (Open State): If you have Focus, you may play an [Action] spell (Rule 342).
• If the chain is not empty (Closed State): You may only play [Reaction] spells (Rule 309.1.a).

Summary Table: Playing Spells on Opponent's Turn

*Note: You cannot react to the act of your opponent playing a unit or gear from their hand, as these do not linger on the chain (RiftJudge FAQ #5909). You can only react to triggered abilities that occur AFTER they enter the battlefield.

Key Rule References:

• Rule 309.1.a: Only [Reaction] cards/abilities can be played in a Closed State.
• Rule 342: A Showdown creates an Open State where players may play spells.
• Rule 158.2.b: [Reaction] keywords grant all the permissions of [Action], plus the ability to be played during any Closed State.

If you are unsure if a specific card interaction allows you to play a spell, please provide the name of the cards involved!