When Trial of Knowledge enters, draw three cards, then discard a card.
When a Cartouche you control enters, return Trial of Knowledge to its owner’s hand.
Each Trial has an ability to return to your hand when a Cartouche enters the battlefield under your control. The Trial is returned to its owner's hand only if it's on the battlefield as the ability resolves.
Random a card of Magic: The Gathering (MTG), but you can also roll the D20 dice, random a Planeswalker, have fun with the random rules and more.