Court of Cunning is a rare Enchantment card from Commander Legends (CMR), collector number 63. Current market price: $4.28 (foil $4.40), TCGplayer market prices via Scryfall.
When this enchantment enters, you become the monarch. At the beginning of your upkeep, any number of target players each mill two cards. If you're the monarch, each of those players mills ten cards instead. (To mill a card, a player puts the top card of their library into their graveyard.)