In Rootword, each player builds and scores words by playing roots, extending the roots with more letters, and then finishing them off with yet more letters. Longer words are worth more, so extend your roots as long as you like, but watch out! Any root still on the table can be stolen by another player if they can extend it. (from the rulebook)

Letter Cards Deck (104 cards)
Turn Summary Cards Deck (6 cards)
Rules Document