Spades is a card game that requires a team of players (i.e., an IRL player and an AI teammate) to achieve a combined score of 500 points via trick-taking play. The player attempts to take a set of four cards, known as a trick, from the center of the table each round. The term also refers to tricking other players to respond in certain ways.
The player, their teammate, and the members of the other team receive 13-card hands to start. Each player must discard a card to create a trick. All cards range from 2 at the lowest-value end to Ace at the highest end after King. That said, Spades in general trump Aces and other cards in a trick that leads with another suit. When the lead card is a Spade, gameplay with Spades follows the standard value range.
Each player begins by guessing the number of tricks they believe they can take before the end of the round. A player can select 0 (Nil), which means that they promise not to take any tricks. If they break this promise, they receive a penalty from their combined score with their teammate. If they complete the task, they receive a bonus. They can also select Blind Nil, which doubles their bonus if they keep their word and doubles their penalty if they break it.
Otherwise, the player chooses between 2 and 13 tricks. If they miscalculate, they receive a penalty of zero points. If they overtrick, or take too many tricks, the extra sets or "bags" of four cards are added to a combined total for the team. If the team accumulates 10 bags, the game gives them a 100-point penalty.
Spades doesn't allow the player that leads to play a Spade unless someone previously played one. All players must use suit-matched cards that follow the lead card unless no more remain in their hand.