Gnav is a traditional round game played in Norway, and formerly also in Denmark, with a special pack of 42 cards. It can also be played with a set of pieces shaped rather like chess pawns. When stood on the table they all look the same, but when they are lifted up, the different values can be read on the base. Gnav is closely related to the old Italian game Cuccù, the German Hexenspiel (witches game) and the Swedish Byteskille. A variant known as Slabberjan is played in Zeeland, in the Netherlands, where it was imported by Dutch sailors in the 18th cemtury, when there was a substantial timber trade between the two countries.
The set consists of two of each of the following, listed in order from highest to lowest:
Gjøk (cuckoo), Dragon (knight), Katt (cat), Hett (horse), Hus (house), XII, XI, X, IX, VIII, VII, VI, V, IV, III, II, I, O, Potte (pot), Ugle (owl), Narr (fool).
There can be from 2 to 20 or even more players, and each starts with an equal supply of matches or tokens. The loser of each hand - the player with the lowest card or piece - has to pay one token to the pool. Players who have lost all their tokens drop out of the game, and the last person left in after everyone else has been knocked out is the winner.
The dealer mixes the cards or pieces and gives one to each player. The players look at their own card or piece, without showing its value to any other player. Starting to the left of the dealer and continuing clockwise, each player may choose to keep his card or piece (saying "jeg står"), or may try to swap it with his left-hand neighbour ("jeg byte"). When the player to your right tries to swap with you, you cannot refuse, unless you hold one of the top five cards/pieces, which are called matadors. When a player tries to swap with a matador, the owner of the matador keeps it and there are further consequences as follows:
This continues until the dealer is reached. The dealer can try to swap with the top card drawn from the undealt part of the deck, or with a new piece drawn out of the bag, with the same consequences as above if that card or piece is a matador. If the dealer has a horse or house, a player to dealer's right who tries to swap with the dealer will have to swap with a drawn card/piece instead. If a horse or house is drawn, draw another card or piece.
After everyone has had their turn (or a cuckoo appears), all players show what they have. The player with the lowest piece or card has to pay a token to the pool. If two players are equal lowest they both have to pay a token.
There are special rules for the fool. It is the lowest card/piece, and if you are dealt it you must knock the table to warn everyone that you have it. Obviously your right-hand neighbour will not try to swap with you, but you should try to swap the fool with the player to your left. At the end, both the holder of the fool and the holder of the next lowest piece or card must pay a token. If there are two fools dealt, the two players who hold them after the swapping round must each pay a token, but they are allowed to sit out of the next round of play.
Torkild Grimsrud's Gnav web site has rules and information about Gnav in Norwegian and English.
The Zeeland game Slabberjan is also played with 42 pieces - it does not exist in card form so far as I know. The set of pieces and their order are slightly different from Gnav. From high to low they are:
Ruiter or Kap-af (knight), Vogel (bird), Poesje (cat), Herberg (inn), 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0, Wittebrood (white bread) or Meelzak (flour sack) or Blind, Pispot (chamber pot), Smoel (scary face), Jan Rit (fool).
So instead of a horse there is a blank piece (white bread) ranking immediately below the zero.
The knight has the same function as the cuckoo in Gnav - the player who tries to swap with it must pay, and trading stops. The bird simply refuses to trade - the player who tries to swap with it must keep his card but does not have to pay a penalty. When someone tries to swap with the cat, all trades up to that point are undone, and the innkeeper when asked to swap says "pass the inn" causing the trade to be with the next person in turn instead.
Rules and further details of this game are available on this archive copy of the Dutch site Slabberjan. The same text, without illustrations, is available in the Zeeland Wiki Zeeuwefavoriten.