Arguably one card (and then more cards in their joke sets) that doesn't actually randomly choose, which they won't reprint [1], and which they've banned because

Arguably one card (and then more cards in their joke sets) that doesn't actually randomly choose, which they won't reprint [1], and which they've banned because of the way it works [2]. And the cards that force reshuffling do require time and effort, but not in a way that breaks the game. They wouldn't make a card that required you to shuffle your deck five times a turn, but they could do so online. [3] [1]It's on the Restricted List -- cards that won't ever be reprinted, but not because of power; to let the cards keep their value. http://www.wizards.com/Magic/TCG/Article.aspx?x=magic/products/reprintpolicy http://www.wizards.com/Magic/TCG/Article.aspx?x=magic/produc... [2]http://www.wizards.com/Magic/TCG/Article.aspx?x=magic/faq/unhinged http://www.wizards.com/Magic/TCG/Article.aspx?x=magic/faq/un... [3]What would that card be, you ask? I have no idea. It doesn't matter for the sake of this discussion.