Hearts
Image source: By Bermicourt - Own work, CC BY 4.0
Summary
A game of Hearts for four players consists of thirteen tricks. First, shuffle a standard deck of cards. Each player receives thirteen cards. For each trick, players play one card to the trick. The first player will set the lead suit for the trick, which subsequent players must follow suit if they can, otherwise they may play any card from their hand. Also, the first player is restricted to not play a card from the Hearts suit unless one has already been played. Once all cards have been played, the player who played the highest card that matches the suit of the led card will collect all the cards in the trick and become the first player for the next trick. Once all tricks have been played, players earn one point for each ♡ collected in tricks, plus 13 points if they collected the Q♠. If a player happens to collect all ♡ and the Q♠, then they will Shoot the Moon and instead subtract 26 points from their score. The player with the lowest point value wins the game.
Rules Source
These rules are summarized from https://www.pagat.com/reverse/hearts.html.
Variants Used
Hearts in Valet does not include the ability to pass cards before playing the game. Also, instead of playing multiple rounds until one player scores over 100 points, only one round of play is included.
Related Games
Hearts is a reverse trick-taking game. Other related games in this genre include Gong Zhu, Knaves, and Reversis.
Information Flow
The diagram above visualizes information flow in Hearts using a single random rollout in CardStock. Visibility is attached to card locations, so all cards in a location share the same visibility; information is revealed or concealed as cards move between locations and ownership changes.
Public locations are shown in green, hidden locations in yellow, private locations in blue, and memory locations in light gray. Locations containing cards with distinct backs are indicated with bold borders. Rectangles denote ownership (players or table), and directed edges show card movement between locations and resulting visibility changes. Taken information is shown with red dotted edges (public to private/hidden), and shared information with blue dashed edges (private cards transferred to another player).
RECYCLE Code
The rules for Hearts are coded in RECYCLE, a card game description language, to encourage standardized implementations across different systems.
You can also Download the code.
;; Hearts
;; https://www.pagat.com/reverse/hearts.html
(game
(setup
;; Set up the players, 4 players each on their own team
(create players 4)
;; Create the deck source
(create deck (game iloc STOCK)
(deck (RANK (A, TWO, THREE, FOUR, FIVE, SIX, SEVEN,
EIGHT, NINE, TEN, J, Q, K))
(COLOR (RED (SUIT (HEARTS, DIAMONDS)))
(BLACK (SUIT (CLUBS, SPADES)))))))
;; Stages of the game
(do (
(set (game points SCORE)
(((SUIT : HEARTS) 1)
((RANK : Q) (SUIT : SPADES) 13)))
(shuffle (game iloc STOCK))
(all player 'P
(repeat 13
(move (top (game iloc STOCK))
(top ('P iloc HAND)))))
(set (game str LEAD) NONE)
(set (game sto BROKEN) 0)))
;; players play a round 13 times
(stage player
(end (all player 'P (== (size ('P iloc HAND)) 0)))
;; players play a hand once
(stage player
(end (all player 'P (== (size ('P vloc TRICK)) 1)))
(choice (
;; if first player and hearts not broken and have non-hearts cards
;; play one of these, remember it in the lead spot, and end your turn
((and (== (game str LEAD) NONE)
(== (game sto BROKEN) 0))
(any (filter ((current player) iloc HAND) 'NH
(!= (cardatt SUIT 'NH) HEARTS)) 'C
(do (
(move 'C (top ((current player) vloc TRICK)))
(set (game str LEAD) (cardatt SUIT (top ((current player) vloc TRICK))))))))
;; if first player and hearts not broken and all cards hearts
;; play any card, remember it in the lead spot, and end your turn
((and (== (game str LEAD) NONE)
(== (game sto BROKEN) 0)
(== (size (filter ((current player) iloc HAND) 'NH
(!= (cardatt SUIT 'NH) HEARTS))) 0))
(any ((current player) iloc HAND) 'C
(do (
(move 'C (top ((current player) vloc TRICK)))
(set (game str LEAD) (cardatt SUIT (top ((current player) vloc TRICK))))))))
;; if first player and hearts broken
;; play any card, remember it in the lead spot, and end your turn
((and (== (game str LEAD) NONE)
(== (game sto BROKEN) 1))
(any ((current player) iloc HAND) 'C
(do (
(move 'C (top ((current player) vloc TRICK)))
(set (game str LEAD) (cardatt SUIT (top ((current player) vloc TRICK))))))))
;; if following player and cannot follow SUIT
;; play any card, and end your turn
((and (!= (game str LEAD) NONE)
(== (size (filter ((current player) iloc HAND) 'H
(== (cardatt SUIT 'H)
(game str LEAD)))) 0))
(any ((current player) iloc HAND) 'C
(move 'C (top ((current player) vloc TRICK)))))
;; if following player and can follow SUIT
;; play any card that follows SUIT, and end your turn
(any (filter ((current player) iloc HAND) 'H
(== (cardatt SUIT 'H)
(game str LEAD))) 'C
((!= (game str LEAD) NONE)
(move 'C (top ((current player) vloc TRICK))))))))
;; after players play hand, computer wraps up trick
(do (
;; solidfy card recedence
(set (game points PRECEDENCE)
(((SUIT : (game str LEAD)) 100)
((RANK : A) 14) ((RANK : K) 13) ((RANK : Q) 12)
((RANK : J) 11) ((RANK : TEN) 10) ((RANK : NINE) 9)
((RANK : EIGHT) 8) ((RANK : SEVEN) 7) ((RANK : SIX) 6)
((RANK : FIVE) 5) ((RANK : FOUR) 4) ((RANK : THREE) 3)
((RANK : TWO) 2)))
;; determine who won the hand, set them first next time, and give them a point
(set (game str LEAD) NONE)
(cycle next (owner (max (union (all player 'P ('P vloc TRICK)))
using (game points PRECEDENCE))))
;; if winner played trump and trump not broken, trump is now broken
((and (!= (size (filter (union (all player 'P ('P vloc TRICK))) 'PH
(== (cardatt SUIT 'PH) HEARTS))) 0)
(== (game sto BROKEN) 0))
(set (game sto BROKEN) 1))
;; discard all the played cards
(all player 'P
(move (top ('P vloc TRICK))
(top ((next player) vloc TRICKSWON)))))))
;; determine score
(stage player
(end (all player 'P (== (size ('P vloc TRICKSWON)) 0)))
(do (
((== (sum ((current player) vloc TRICKSWON) using (game points SCORE)) 26)
(dec ((current player) sto SCORE) 26))
((!= (sum ((current player) vloc TRICKSWON) using (game points SCORE)) 26)
(inc ((current player) sto SCORE)
(sum ((current player) vloc TRICKSWON) using (game points SCORE))))
(repeat all
(move (top ((current player) vloc TRICKSWON))
(top (game vloc DISCARD)))))))
(scoring min ((current player) sto SCORE)))