Activate

To activate (Japanese: Hatsudō) a Magic/Trap Card is to play it on the field face-up, either from your hand or Reversing it face-up after it was Set, and usually you declare that you want to apply its effect if it has any. Trap Cards and Instant Magic Cards cannot be activated during the same turn they were Set.

To activate an effect is to declare that you want to apply it. This goes for Reverse, Trigger, Ignition and Quick Effect of Effect Monsters and also for Trigger-like, Ignition-like or Quick-like Effect of Magic/Trap Cards. Effects can be activated not just when the card is face-up on the field, but also in the hand, Graveyard, Banished Zone, Main and Extra Deck, depending on what the card says.