Trivia Contest is one of those cards players keep asking about. Here is, in plain words, what its official text says, the rulings published by Wizards of the Coast, and the combos players actually run.

Official card text

Visit — An opponent chooses black card, artifact card, or expansion, then mills a card. You have ten seconds to name something from the chosen category that starts with the same letter as the milled card. If you do, claim the prize! Prize — You get , then you may put a sticker on a nonland permanent you own. Sacrifice Trivia Contest and open an Attraction.