mtg.wtf

Visit — An opponent chooses green card, instant card, or named mechanic, 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 {TK}{TK}{TK}, then you may put a sticker on a nonland permanent you own. Sacrifice Trivia Contest and open an Attraction.