Double Handed Hearts
Since the inception of Windows almost everyone is familiar with the game of Hearts. This is a firm favourite between my friends and we play a vast amount - up to the point where you can be expecting everyone to be, in some amount, counting cards, bluffing, and calculating odds.
One of the major issues with the game is that it requires four players. For a situation in which only two players are present we invented a variation where by each player plays the game with two consecutive hands. The rules are largely the same, and for an individual, each hand can be considered a player in its own right, just on the same team. From then on the rules follow as normal with a couple of exceptions -
There is an addition to the winning conditions. A player loses if ANY of his hands reach 100 points.
There is also a modification to shooting the moon. Upon shooting the moon both player hands receive no points, while each opponent hand receives 24 points.
Although only a slight variation on the game of Hearts, the consequences are much larger, and lead to a interesting number of new gameplay elements.
Knowledge of the Deck
As all the cards are dealt and there are two players, each player has full knowledge of what cards they have, and therefore what cards the other player has. The interesting development is that one cannot be sure which hand the other player holds a certain card in, only that he holds it.
An immediate implication of this is that you know on deal which player has the queen of spades. This can allow you to adjust your game plan appropriately. If you lack the queen you might avoid passing any spades to try and out her, and if you have the queen you might adjust such that you can get rid of her as soon as possible. If you are feeling bold you can even anticipate this and pass the queen to your opponent, in the hope they will be unprepared for it.
Finally it gives you a great overview of what kind of suites the other player has in what quantity and what he may be attempt to go void in.
Passing to yourself
When at the beginning of the game, if the pass direction is left or right, you have the ability to pass cards from one of your hands to the other. This makes the passing phase much more tactical. No longer is it just a way to hand off bad cards. One can construct a whole game plan before any hands are even played.
One common tactic is that presence of the queen in one hand makes passing spades in the other hand a valid option as you can be sure you wont be passed the queen and that your spades will not help your opponent out the queen. Alternately you can pass many of a suite from one hand to the other to ensure being void in that suite without "losing" low number cards to an opponent.
Other tactics include passing high cards from one hand to another in an attempt to shoot the moon, or passing the queen to a hand with a larger number of spades that could shield her. There are all kinds of tactics that one can play but essentially passing to your own hand gives you better safety in at least one of your hands as you know what you will receive.
Forcing the Queen
Having control of two hands opens up a fun tactic. In some cases it is possible to force the queen upon one of the hands of your opponent. The basic setup is simple. It requires one of your hands to have the queen and to be void in some non-spades suite. The other hand needs either the 2 or 3 in this suite and to gain the lead. Once this hand gains the lead it plays the 2 or 3, and providing the other player has a card in that suite you can be assured to give him or her the queen without your other hand receiving it.
This setup or a variation of, is actually more common than you would expect - and so being wary of an early queen deployment is very key - in particular on pass left or pass right hands.
Sharing Points
As a player loses if either of their hands reach 100 points it is somewhat natural to try and spread point distribution across each of your hands. This means that a hand doing well in the game can take some flack in another hand receives a bad deal. Another option is that at the end of a game, when one of your hands cannot lose lead and is receiving all the hearts it can be possible to force the lead onto your other hand so that to maintain an even spread of points.
Shooting the Moon
With the knowledge of the deck, the ability to pass to yourself, and some notion of teamplay the game is already far more tactical. In many cases a player can really manipulate a hand to fit a certain gameplay style. All of this obviously makes shooting the moon somewhat easier. In fact there are many more cases when one can force shooting the moon rather than having to bluff to some degree to open up the game and have the higher cards played.
Shooting the moon is also somewhat better because your other hand does not receive any points against it. This means that players will more often try to shoot the moon and it needs to be guarded against. It is all too easy to have such extreme hands in double handed hearts so that lead gets stuck and cannot be retrieved.
Conclusion
Thinking for two people at once is not easy and so if you are a person who needs to be certain of a move before they play, this game is not for you. It is very difficult to hold the whole game in your head and to play requires a more tactical, lenient attitude. If unsure of how to play, just separate each hand conceptually and try to play the best defensive game for each - often this is very effective.
If you have the guts you should give it a try. The first few rounds can be slow and painful but if you are a Hearts fanatic like me you will see that it really is a cool development on the classic game which puts emphasis on extreme tactics and smart gameplay.