Learn

Learn is a keyword action introduced in Strixhaven: School of Mages.

Description
If spell or ability instructs you to learn, you may do nothing or do any of the two following choices. Your first choice is that you can discard a card and then draw a card. This is a great way to improve your hand, trading in extra lands or trading out undesirables for a chance at what you need. Your second choice is to reveal a Lesson card from outside the game and put it into your hand. Lesson is a spell type seen on instants and sorceries. There is a wide variety of Lesson cards to represent a wide variety of areas of study (e.g. Token generation, removal, card draw, etc.).

Learn has similarities to Investigate (a rider that appears on many cards as an extra resource), Aftermath (a single card producing two different spell effects), and interestingly Contraptions (a selection of outside resources that is activated by otherwise weaker cards).

Rulings

 * If a card is brought into the game from outside the game, it will stay in the game until it ends or until its owner leaves the game, whichever comes first.
 * If you bring a card into the game from outside the game in a Constructed tournament (or a Constructed game played under tournament conditions), you may select only a card from your sideboard. In casual Constructed games, the card comes from your collection.
 * If you bring a card into the game from outside the game in a Sealed Deck or Booster Draft event, you may select only a card that is in the card pool that you built your deck from.
 * The official Commander rules don't include sideboards, but if you're using them anyway or casually allowing players to get cards from their collections, cards you bring into the game from outside the game can't share a name with any card in your starting deck.
 * If instructed to learn, you may do nothing. Discarding a card and putting a Lesson card into your hand are both optional.
 * Lesson is a new spell subtype found on some instant and sorcery cards in this set. The Lesson subtype has no special rules associated with it.
 * Although you may want to include Lessons in your sideboard if you're playing with cards that instruct you learn, Lesson cards can be included in your main deck like other instant or sorcery cards.