There are three types of effects, which are identified by icons. An effect’s category determines when it’s resolved.
Immediate effects are conclusively resolved right away when played. Example: “Draw one card.”
Ongoing effects continue to affect the game for as long as their effect text is visible. When it’s covered by another card, the effect ends. Example: “Your draw limit is increased by one card.”
Responses can only be played during another player’s turn in response to some action that player has just taken. Response cards are the only cards that can be played during another player’s turn. Example: “Cancel an Event card as it’s played.”