Duality

Rob Speer

Version 1.0 (August 13, 2006)

Duality: a two-player trick-taking card game

I came up with Duality when I was on a train from Albany to Boston with my girlfriend. I created my ideal two-player card game by mixing gameplay elements from California Jack, German Whist, and Bridge.

In Duality, the bidding overlaps with the trick-taking. The result is a game where you often have to plan for the game to play out two ways: one where you declare trump, and one where your opponent does. That, and the fact that all the twos are laid out on the table, lead to the name "Duality".

Overview

The object of Duality is to get the most points by taking tricks and succeeding in making your bid, or causing your opponent to fail in making theirs. The game ends when at least one player reaches a predefined number of points; 50 or 100 are reasonable choices.

Figure 1: The starting layout.

There are 48 cards in the deck; the twos are taken out beforehand, and are put on the table, representing the suits you can bid on. The cards in the deck have the usual rank order, with 3 being low and ace being high.

Each player gets 12 cards. The players play 12 tricks during which they draw new cards and bid on what suit should be trump, followed by 12 more tricks which count toward making the bid.

Gameplay

The bidding phase

The bidding phase consists of 12 tricks that are played like this:

• Turn the top card of the deck face up.
• The winner of the previous trick leads a card. (The dealer has the first lead.)
• The other player responds with a card, following suit if possible.
• The winner of the trick can use that trick to bid, as described below.
• The winner of the trick takes the face-up card and adds it to her hand.
• The loser of the trick reveals the next card in the deck and adds it to his hand.

Begin by flipping the top card of the deck face up. The dealer leads first, and at this point there is no trump.

Figure 2: The top player wins the trick with the 10 of hearts.

Figure 3: Having taken the trick, the top player bids on clubs. She is now the declarer, and clubs are trump. She also takes the jack that was showing on top of the deck.

For each trick, one player leads a card, and the other player responds, following suit if possible (figure 2). As with most trick-taking games, the higher card of the suit led wins (aces are high), and if the second player cannot follow suit, he wins the trick if he plays a trump card and loses if he plays some other suit.

The winner of the trick then has the option of using that trick to bid on a suit. Make a bid by placing the two cards face down next to the 2 of that suit, on one's own side of the table. The bid can also be placed off to the side of the twos, indicating a bid for no trump. If the winner declines to bid on a suit, the cards should go into a designated "trash heap".

If a player's bid on a suit -- that is, the total number of tricks he has placed on that suit -- becomes higher than any previous bid, that suit immediately becomes trump, and the player who made the bid becomes the declarer. (If you happen to be void in a suit, you can use this new trump to take tricks during the bidding phase!) Move the two toward that player to indicate that he is the declarer (figure 3).

Figure 4: The bottom player reveals the next card in the deck, then takes it into his hand.

A trump suit will always be created when the first bid is made, but the trump and the declarer are likely to change a few times as the bidding goes on.

The winner of the trick then takes the top card of the deck, and the loser reveals the card under it to both players and then takes it (figure 4). These cards go into the respective players' hands. So it is not always desirable to take a trick -- in many cases, you may expect the hidden second card to be a better card than the one that is showing. Remember, however, that you can only bid on a suit after taking a trick.

Figure 5: The next card in the deck is flipped to prepare for the next trick.

Figure 6: The deck is empty and the bidding phase is over. The bottom player is the declarer, and spades is trump.

When both players have taken their new cards, flip over the top card of the deck to prepare for the next trick.

As the bidding goes on, it is likely that both players will make bids on their sides of the cards. Remember that to change the trump, it is necessary to exceed the previous highest bid, not just equal it.

In the example to the right, the top player starts by bidding on clubs. By the end of the round (figure 6), the top player has changed her focus to hearts, bidding three tricks on it, but the bottom player has become the declarer by bidding four tricks on spades.

The scoring phase

Figure 7: All bid cards except for those making up the winning bid have been cleared out of the way, and the scoring phase begins.

After 12 tricks have been played in the bidding phase, the deck runs out of cards; this begins the scoring phase, in which the players take tricks that will actually count toward their score. To begin the scoring phase, clear out all of the bid cards on the twos except for those that form the winning bid, and put them in the trash pile. The trump suit is now fixed, and no more bids can be made. The declarer will have to pay for the advantage of choosing the trump, though, by setting aside the number of tricks that he bid. These tricks that are set aside are called the "book", in an analogy to bridge. (Don't stretch the analogy too far, because the scoring is not very similar to bridge.)

A trick is now played like this:

• The winner of the previous trick leads a card.
• The other player responds.
• The winner of the trick adds it to his scoring pile -- except that the declarer must put enough tricks in his "book" before he can start his scoring pile.

The goal in this phase is to take more tricks in your scoring pile than the other player, not counting the book tricks that the declarer sets aside. Each trick is worth 1 point, and the player who scores more tricks gets a bonus of twice the bid. (One way to think of this is that the tricks in the book, as well as the tricks sitting on the 2 that make up the bid, are awarded to the winner.) If both players take the same number of tricks after book, the round is a draw. In that case, each player gets a bonus equal to the bid, so both players get the same number of points.

The effect is that if you win as the declarer, by taking more tricks than the other player after setting some of them aside, you get back the tricks you set aside and more. The total number of points awarded in a round is equal to 12 plus the bid, so in a typical round, 14 to 18 points are divided between the players.

What a bid means

Suppose you are the declarer, having bid three tricks on hearts. You take 8 of the last 12 tricks, so your opponent takes four. Three of these tricks go into your book, and the other five go into your scoring pile. Your opponent has four tricks in her scoring pile. You scored more tricks, so you win. You get the five points you scored plus a bonus of six for winning. Your opponent gets the four points she scored.

If you had taken one fewer trick, then you would have scored four and your opponent scored five, so your opponent would get the six extra points.

That's how the mechanics of the game work, but let's get to the point: how many tricks total do you have to take to win a round? The way it works out, each trick you bid is promising to take another half a trick in the scoring phase, starting at 6. (Half tricks matter because they can make the difference between winning and tying.)

Some examples:

• If you bid 1, your goal is 6.5 tricks. In order to win, you have to beat that goal, by taking 7 or more tricks.
• If you bid 2, your goal is 7 tricks. In order to win, you have to beat that goal by taking at least 8. If you take exactly 7, the round is a tie.
• If you bid 3, your goal is 7.5 tricks, so you need to take at least 8 to win.
• If you bid 4, your goal is 8 tricks, so you need to take 9 to win or 8 to tie.
• If you bid 5, your goal is 8.5 tricks, so you need to take 9 to win.
• If neither player bids, the result is the same as if both players had bid 0 in no trump; each trick is simply worth one point.
• If you bid 9, you will need to beat a goal of 10.5 tricks by taking all but one trick.
• If you bid 11, there is only one trick you're not setting aside, so you will need to take all the tricks.

Remember that counting half-tricks like this is not how you actually count the score; it's only a useful aid to tell how many tricks you need to take.

Rare events in gameplay

Jumping

You may find you want to place a large bid, but you don't have the time to place down that many tricks on the suit. This is where jumping, an analogue to bidding slam in Bridge, is useful. In the bidding phase, if you feel you are going to take almost all or all of the tricks, you can increase your bid to a large number without having to take that many tricks in the bidding phase.

When you take a trick and you make a bid with it, instead of simply adding 1 to the bid, you are allowed to instantly increase your bid to 9 or more. This is called jumping. To do this, shove all the bid cards together into a pile on top of the two and say "nine", "ten" or "eleven". You are allowed to jump more than once.

If you jump and successfully win the round, you will receive a bonus to your score on top of the already large number of points you win: +5 extra points if you bid 9, +10 if you bid 10, and +25 if you bid 11.

Realize that to win a bid of 10 or 11 -- that is, to beat your opponent after setting aside 10 or 11 tricks -- you will need to take all of the tricks. The only reason to bid 10 is as a "safety net", because you can still tie if you take all but one trick.

You can refer to a bid of 9 as a small slam, 10 as a waffle slam, and 11 as a grand slam.

Trick debt

Suppose a round goes really badly for you, and you don't even take enough tricks to set them aside as your book. (For example, you bid 9 -- hoping to take eleven tricks and get the bonus -- but you only take 8.) The result is a trick debt.

When this happens, your get no score for the round, and your opponent gets all the points available in the round (12 plus the bid) plus 5 points for each trick you are in debt. This will make your opponent's score surge way ahead relative to yours, a reward for thoroughly kicking your ass on defense.

One reason for this penalty is to discourage the possible tactic of suicidally bidding a slam you won't even come close to winning, just to stop your opponent from picking the trump suit.

Don't confuse trick debt, which is failing to even take the tricks you need to set aside, with the much more ordinary situation of losing a round. When you lose a round, you take fewer tricks in your scoring pile than your opponent does; when you go into trick debt, you don't have any tricks in your scoring pile, because you didn't even finish making your book.

Strategy

Some strategic tips:

• Toward the beginning, you want to keep both high and low cards around, so that you can win or lose a trick as you choose. High cards will, of course, be more useful in the long run.
• Trumps are even more important to collect than high cards. If you know what trump will be, you will want to spend high cards to get trump cards. If you have more trumps than your opponent, those are almost certainly going to be free tricks in the scoring phase.
• On that note, only seriously bid on a suit if you are on your way to having over half of the suit in your hand. Try to have 5 trumps when you begin bidding up the suit, so you can have at least 7 when the bidding phase ends.
• Early in the bidding phase, if you can, become void in a suit that's not one of the two leading suits. This gives you the flexibility to trump if you need to, and also means you have longer suits.
• There's nothing wrong with switching what suit you bid on. You may even want to deceptively bid one suit before switching to your real preferred trump suit, hoping that your opponent will throw away potential trump cards.

Scoring table

You don't need this table to score a game of Duality, but it can help you tell what the possible outcomes of a round are and decide on a strategy for how high to bid.

The numbers across the top are how much you (the high bidder) bid, and those down the side are how many tricks you take. The numbers in the grid are the resulting difference between your score and your opponent's.