Quick-Play Spell Cards known as Instant Magic Cards in the OCG are a type of Spell Card with a Spell Speed 2, and can be activated from the player's hand during any Phase of their turn. They can also be activated during the opponent's turn, if they have been Set. Cards like "Scapegoat" and "Rush Recklessly" are examples as Quick-Play Spell Cards.
RulesPlayers may activate Quick-Play Spell Cards from their hand during their own turn, but cannot activate them from their hand during the opponent's turn.
Face-down Quick-Play Spell Cards can be activated during either player's turn. However they cannot be activated the turn they are Set. i.e. When a player Sets a Quick-Play Spell Card during their own turn, they cannot activate it until the beginning of their opponent's next turn.
Quick-Play Spell Cards can be chained to other cards.
Example
Player A activates "Dark Hole".
Player B chains "Imperial Order".
Player A chains "Mystical Space Typhoon" from their hand.
Example