Quick Effect
Quick Effects (previously known as Multi-Trigger Effects) in general, can be activated either during your turn, or your opponent's turn. They are the only Monster Effects that are Spell Speed 2.
Monsters effects that negate the activations or the Summons are all Quick Effects. Monsters that have other Quick Effects usually have: "This effect can be activated during either player's turn", or something similar in its card text. The card rulings may also indicate if the effect is Quick or not.
Following the Problem-Solving Card Text, any effect that has "During either player's/your opponent's turn:" or similar text, is a Quick Effect. Some monsters like "Swift Scarecrow" may indicates in its text that the effect is a Quick Effect.
Some Quick Effects can be activated more than once in a chain, while others cannot.
- Example #1: "Horus the Black Flame Dragon LV8" exists on the field, your opponent activates "Fissure". "Horus the Black Flame Dragon LV8"'s effect immediately activates since "Fissure" is a Spell Card. Your opponent replies by chaining "Book of Moon", and again, you can activate the effect of "Horus the Black Flame Dragon LV8" because it has a Multi-Trigger Quick Effect.
- Example #2: "Light and Darkness Dragon" exists on the field and your opponent activates "Fissure". "Light and Darkness Dragon"'s effect activates as a chain to "Fissure". Your opponent replies by chaining "Book of Moon", but because "Light and Darkness Dragon" has a Trigger Quick Effect rather than a Multi-Trigger Quick Effect, it cannot be used more than once in a chain and therefore cannot negate "Book of Moon"'s activation.
see List of Quick Effect Monster Cards
