Study Hall is a common Land card from Commander 2021 (C21), collector number 80. Current market price: $0.24, TCGplayer market prices via Scryfall.
{T}: Add {C}. {1}, {T}: Add one mana of any color. When you spend this mana to cast your commander, scry X, where X is the number of times it's been cast from the command zone this game.