Card Games/Jass games

There is a large family of point-trick card games with the distinguishing feature that Jack and Nine of the trump suit are the highest trumps. The names of these games are often a variation of "Klaverjas", being Dutch for Jack of clubs. This suggests that in an earlier form of the game, clubs was a permanent trump suit. Modern games of this family include the Dutch national card game Klaverjas, the French national card game Belote, and the Swiss national card game Jass. Games of this family are also popular in some locations in North America, in Jewish communities, in the Balkans and the Middle East, and in South Asia.

Cards, ranks and points
Almost all games in this family are played with decks of 24–36 French-suited playing cards. A notable exception is formed by Jass (played in Switzerland and Vorarlberg), which depending on the region is played with French-, Swiss- or German-suited cards. In most variants the point values of cards are as shown in the table. The deck shown here has 36 cards, like the one used for Jass. The most typical deck for other variants is the piquet deck of 32 cards, which omits the Sixes. Some variants also omit the Sevens and Eights, resulting in a deck of 24 cards. The ranks of the cards are also as indicated by the table. In particular the aces and tens rank high (i.e. before the kings), and the Jack and Nine of the trump suit (if any) are promoted to become the two highest ranking trumps. However, two variations occur frequently enough that they are worth mentioning here.

Tens may rank low: While normally the tens rank between the aces and kings as one would expect for a card that counts almost as much as an ace and twice as much as a king, in some variants of the game the they rank low, i.e. immediately above the nines. As a result these very valuable cards (in terms of scoring points) are quite easy to lose in a trick.

Picture card values may be lower by one: In some variants of the game the King, Queen and (non-trump) Jack score 3, 2 and 1 points, respectively, i.e. each one point less than normal.

Basic game play
There is great variation in how trumps are determined, e.g. by bidding, auction or putting a card face up, which may happen before all cards have been dealt. In some variants no trump is also an option, and in this case almost all variants agree about the rules for trick-play.

The first player (usually forehand, i.e. the player who sits after the dealer and received the first cards) leads any card to the first trick. Each player in turn contributes one card. Players must follow suit, i.e. play a card of the same suit as the first card in the trick, whenever possible. Only a player who is blank in the suit led is allowed to discard a card of another suit instead. The player who contributed the highest-ranking card of the suit led takes the trick, placing it face down on a stack in front of the player. The first player in each subsequent trick is the player who won the previous trick.

All rules agree that if a trump suit has been chosen, any trick containing a trump is won by the player who contributed the highest-ranking trump, even though the suit led may have been a plain suit. There is, however, considerable disagreement about the precise rules that answer the question when it is allowed to play a certain trump.

Once all cards have been played, each player wins the total point value of the cards in the tricks won by that player. More points may be added for:
 * melding certain combinations of cards before the first trick, or
 * capturing certain combinations of cards in a single trick; and
 * winning the last trick.

Trumps
In the course of trick-play, players will occasionally trump a trick that started with a plain suit. And sometimes a player will lead a trump, resulting in a round in which every player overtrumps the previous players, if possible. These are typical situations in most Jass games, but different variants and sub-variants disagree about the details: When exactly can, or even must, a trump be played into a trick? This variability seems to be inherited from tarot games such as French Tarot; it can be regarded as the result of codifying the character of trumps in different ways: These characteristics of the trump suit set the Jass family apart from most other modern trick-playing games, which typically treat trumps in the same straightforward way as whist does: In whist, trump is governed by exactly the same rules as all other suits. It merely happens to win the trick in some situations.
 * Trumps want to trump tricks which hitherto consist only of cards in plain suits.
 * Trumps do not want to undertrump, i.e. be played to a trick that already contains a higher trump.

For describing the precise rules that govern trick-play the following terminology will be convenient:


 * Follow plain suit: Play any card of the suit led. Does not apply if the suit led is trump.
 * Follow trump suit: Play any trump. Only applies if the suit led is trump.
 * Trump: Play any trump.
 * Overtrump: Play a trump that ranks higher than all trumps already in the trick. This includes playing the first trump to a plain suit led trick.
 * Undertrump: Play a trump that ranks lower than the highest-ranking trump in the trick.

This terminology makes it possible to describe complex rules by a short list of options, with the understanding that every card played is subject to the first applicable and satisfiable condition in the list. Thus it is easy to read from the example in the table above that players in Scarto must follow suit if possible; that a player who cannot follow suit must play a trump if possible; and only a player who is blank both in the suit led and in trumps may discard.

Variants of trick-play rules in Jass games
It makes sense to begin by considering only non-partnership games, and in partnership games the case that the partner has not played yet or does not head the trick. In the case of two-handed games the situation becomes even simpler, because in case a plain suit trick has been trumped no further cards can be played.

It is likely that all Jass games derive from a two-handed Jewish game. David Parlett traced the game back to a Dutch book of 1821 which describes a game called "Smoojas" ("Jewish Jass"). It is played with a 32 card piquet pack. Tens rank low, and picture card values are lower by one. As in many two-handed trick-taking games, there is initially a stock from which players complete their hands after each trick, and players may play any card without any restrictions such as following suit. Once the stock is empty, the rules shown in the table apply. The Wikipedia article for Belot currently describes rules of trick-play for a 2–4 player game which seem to correspond to this rule set. The rules for Manille (not a Jass game, although somewhat related) have the same property, although they differ with those for Belot in the way partnerships are treated.

Perhaps Jewish Jass changed its trick-play rules to those shown in the table under "Most modern games" before the variants for more players branched off. In any case trick-play in the 2-handed Jewish and Hungarian game described by David Parlett under the rubric "Klaberjass" is as shown here (see also John McLeod on Bela ), and almost all modern Jass games agree with these rules in the 2-handed case, or for the second card played in each trick.

The rule sets in the table are ordered from most restrictive to most liberal.

This rule set is as in French Tarot. It is used in Belote, Coinche and the Rotterdam variant of Klaverjas (according to John McLeod and David Parlett). Also the German game Klabberjass described by John McLeod. Also Clabber as played in Indiana. 

This rule set is used in the Amsterdam variant of Klaverjas (according to John McLeod and David Parlett). In two-handed games the situation in the middle column cannot arise, and therefore both rule sets agree.

This rule set is described by David Parlett for the game Grevjass from the Faeroes. The same trick-play rules are used for Boonaken and Staekske Rape.

While there is a great deal of variation in Jass games, and some uncertainty about fine points of trick-play rules since they are so complicated, they are essentially standardised. Sources:, David Parlett,. Rule set for positive Swiss Jass is also used for Pandoeren and a variant of Boonaken.