Uno is a card game that is played with a specially printed deck. It is typically played with two to ten players and the objective is to be the first player to score 500 points. The clue "Half dos" suggests that uno is the next number after the number two, which is dos in Spanish.
Note: The provided meaning of the answer is for the latest New York Times crossword puzzle clue: Game whose name must be said to win. Explanations are generated by AI and may be inaccurate.