A 'card' contains a task to nudge someone into experiencing their environment slightly differently.
Sometimes, a task can be more directive, sometimes it can be more suggestive. A card can be connected to a particular location.
If a task makes someone think more deeply about their surroundings, or discover something they didn't know before, you can consider your task to have been a success.
You can add existing cards to decks, scores and events.
This list of cards includes your own cards, and cards you've hearted.