Tressette Rules
Tressette is played with a standard Italian 40-card deck and the cards are ranked as follows from highest to lowest: 3-2-Ace-King-Knight-Knave and then all the remaining cards in numerical order from 7 down to 4.
The game may be played with four players playing in two partnerships, or in heads-up play. In either case, ten cards are dealt to each player.
In one on one play, the remaining twenty cards are placed face down in front of both players. The object of the game is to score as many points as possible until a score of 21 is achieved. Players must follow suit unless that suit does not remain in their hand, and players must show the card they pick up off the card pile to their opponent.
Scoring
Points are scored by collecting the face cards (King, Horse, Queen), threes, and twos; each of this cards scores ONE THIRD of a point. An ace scores one point on its own. Each player can only score an integer number of points; the thirds of point "in excess" go to the player who scored the last trick. There are 10 and ⅔ points in a deck; the player that scores the last trick is awarded another ⅓ of points, so for each hand 11 points will be scored. The match continues until a score of 21 is achieved.
Strategy
Basic strategy
Basic strategy in tressette revolves around gathering as many Aces as possible because they are worth three times the value of any one face card. As such, players typically attempt to "strip" their opponent of the Three and Two in the suit in which they themselves hold an Ace; at that time, the ace may be played safely and a point scored in their favour. Hence, when holding several lower ranked cards in a suit plus the ace you may play the lower ranked cards in the hope your opponent is forced to play the three or two of the suit allowing you to play the ace. Obviously, holding Ace, Three and Two of a suit (called a "Napolitana", "Napoletana" or a "Napoli") is a particularly powerful holding as it allows you to play the Ace with impunity, careful not to surrender it to an off-suit card. As picking up the last hand garners a point, players try to organize their card play for this purpose near the end of a round.
Partner interaction
When playing in partnerships, any verbal communication between partners regarding the game is considered cheating, unlike in briscola (oral tradition has it that "tressette was invented by four mutes, briscola was invented by four liars"). There are, however, three conventional signs that can be exchanged between partners:
Busso ("Knocking"): The player knocks or raps on the table. This sign can be used only by the first player of the trick. It instructs that player's partner to play the highest-ranked card of the suit being played, in an attempt to win the trick. If the partner does win the trick, he is supposed to play any card of the same suit. This strategy allows a player who has a strong card in a suit (i.e. a 2 or 3) to check whether his partner has the other one, without risking to play both cards on the same trick (thus squandering one high-rank card) and keeping the flow of the game under his control.
Volo ("Flying"): The player lets the card drop or "fly down" from a few inches above the table. This sign signifies that the player has just played his last card of this particular suit.
Striscio or Liscio ("Sliding"): The player slides the card across the table before playing it. This sign signifies that the player has many cards of that suit (where the exact implications of "many" depend on the context, e.g. the number of cards of that suit still in play or the number of cards each player still has.) In some regional variants the use of this sign is deprecated and considered as illegitimate as speaking openly.