Schwimmen belongs to the Commerce group of games, in which you improve your hand by exchanging cards with a central pool of face-up cards. Other names for the game are 31, Schnautz, Knack and Hosen 'runter (trousers down). Although it is known in many parts of the world, it seems to be particularly popular in Germany and the western part of Austria.
There are two other games called 31:
The first version of this description was based on an article posted to rec.games.playing-cards by Christian Moeller, and variations from various sources have been added since.
This game will work with from 2 to 8 players. First of all everybody is given an equal number of chips (the more chips, the longer the game will last - 3 each is reasonable).
You need a normal 32-card deck (7-10, J, Q, K, A) which can be made if necessary by stripping the low cards (2-6) from a standard 52 card deck. The cards have values as follows:
| Card | Value |
|---|---|
| Ace | 11 |
| King, Queen, Jack, Ten | 10 |
| Nine | 9 |
| Eight | 8 |
| Seven | 7 |
The dealer deals 3 cards face down to each player, plus an extra hand of 3 cards. The dealer looks at his 3 cards and decides whether to play with these or with the extra hand - this choice must be made before he sees the cards in the extra hand. The cards rejected by the dealer (either his original hand or the extra one) are now turned face up and put in the middle of the table.
The player to the left of the dealer plays first, and turn to play passes clockwise.
At your turn you have three options:
The turn then passes to the next player. Note that you are never allowed to keep just one card and exchange two.
If you ever have a special combination (either from the initial deal or as a result of exchanging), you must immediately expose it and the hand ends (there is no further chance for the others to exchange). The special combinations are:
If all the players pass in succession, the three face up cards are replaced by three new cards from the undealt portion of the pack (talon). After this the game continues as usual.
If a player decides, at the end of his turn, that he holds enough points he may 'close'. After that every other player has just one more turn and then the hand is finished and the cards are shown.
When the play is over, all the players' cards are exposed. The score for a hand is got by adding up the values of the cards in any one suit. For example: 
7, 9, 
K would count 16 points (for the two hearts); 
8, 
9, J would count 10 (for the jack of spades).
Three of a kind (three cards of the same rank, such as 3 queens or 3 sevens) score 30.5, unless the cards are aces - three aces score 32 as already mentioned. So A, A, A (32) beats A, K, J (31) which beats 9, 9, 9 (30.5) which beats K, Q, J (30).
If the play ends because a player closes, or because of a declaration of 31 (Schnauz), whoever has the worst hand loses one chip. If two hands have the same score, a higher three of a kind beats a lower one (in the order A (high), K, Q, J, 10, 9, 8, 7) and a combination in a higher suit beats an equal scoring combination in a lower suit - the suits rank as in Skat: clubs (high), spades, hearts, diamonds. If both players have the same suit then both players lose. In the rare case of a tie (two equally low scores in the same suit - for example one has King-Ten and the other Queen-Jack in the same suit, both having the third card in a different suit, or one has K-9-6 and the other has 10-8-7 in the same suit)), both players lose.
If the play ends because of a delaration of fire (Feuer), all the players except for the one with fire lose a chip.
If someone has to give away his last chip he said to be 'swimming' (schwimmen in German). He can continue to play, but if he loses another hand he drops out of the game and only the others may play on.
The game continues until all the players except one have been eliminated. The last 'survivor' has won the game and receives a prize.
It may sometimes happen that the last surviving players have equal hands in the same suit when one of them closes. In this case they share the winnings, or if the players really need to find a single winner, then these last players need to play another deal to decide the game.
Jay I. Sharn offers the following advice.
If you want to improve your chances of winning you need to strategically and not rely entirely on luck coming your way.
Try not to show any visible reaction if the game is not going your way (for example if somebody took the card you needed to get a score of 31).
If you need a particular card from the table, do not stare at it, because the other players will observe you and know what card you need. Sometimes yopu may be able to fool the others by staring at an unwanted card.
Assume that each player will have just three turns: games rarely go on longer than this before someone closes.
When you first look at your cards and the table card, form a plan and a backup plan in case the first one fails. For example if your cards are 9H,9D,7H you would make your main objective to get 3 nines but say there is a nine face up and somebody takes it before you can you deduce that it is unlikely for the fourth nine to be present, it is more likely to be in the talon.When it's your go again you find the cards face up are 10H,8D,7S then you could replace your 7D for the 10H so your total is 26 which is reasonably good.
3)You must try and work out the strategies of your opponents by looking at which card they take and which card they put in the middle and then act accordingly.
Some people do not recognise the option of exchanging all three cards. In such a game you must either exchange one card or pass.
If one or more players are dealt 31 in their initial hand, some play that all the players who do not have 31 lose a chip. If someone is dealt three aces (fire) as their initial hand, all the other players lose 2 chips unless they were dealt 31; players with 31 lose 1 chip only.
Some older descriptions of this game do not recognise the "three of a kind" combinations, but most people nowadays do allow these.
Rutger Wimmenhove describes a variant traditionally played in the Netherlands, which differs from the game described above as follows:
When it is your turn you must either exchange or close your game. You cannot pass with the option of exchanging again later. The options on each turn are as follows:
Note that it is not possible to close your game in the same turn after exchanging one card. You must wait until the start of your next turn to close (option 2).
Closing does not bring the game to an end for the other players. They can continue taking turns after one passes; this goes on until only two players are left. If one of those two passes (at the beginning of his turn), the other player can exchange one last time.
Because you must always exchange or close, new cards never enter into play.
Scoring 31 always immediately ends the game. If you make 31, it must be announced immediately and the cards shown. Nobody may exchange another card and the hand is immediately scored. The only exception is if 31 is made in the first round of exchanging: in this case everybody who who has not yet played yet gets one turn; players who already had a turn do not get another. If you are dealt 31, you must immediately declare 31 and open, even if it's not your turn; every other player gets just one turn.
There is no special score for "Feuer": three aces scores just 30.5. If multiple hands of 30.5 are lowest, all those players lose: one 30.5 does not beat another 30.5 based on which cards the trios are.
The score is usually kept using dice: one for each player. Everybody starts at six, and losers turn to make their number lower. The person who is first out of points gets the "Chicken", usually marked with a joker card, a low card from the deck not used for playing or an actual chicken doll, and can lose one more time before they are eliminated from the game. There is only one chicken and it can be used only once during the game. If several people are eliminated at the same time, nobody gets the chicken.
Si-lam Choy describes this variant for 2-10 players in which each player is dealt four cards from a standard 52-card pack and there are four cards face up on the table. Therefore the maximum hand value is 41, and the lowest is 2. At each turn, the player has four options:
If the face down deck runs out, the discarded cards can now become the deck with or without a shuffle.
Si-lam Choy suggests the following scoring system: The winner gains in points equal to the value of his winning hand. The losers lose in points the difference in value between their hands and that of the winner. The biggest loser gets to go first next round. Any ties with the winner are also considered winning hands.
Notes on tactics. At 4 players, it gets interesting because invariably you have competition for a particular suit. For a two person game, the person who goes first has a distinct advantage. Although you can end the game at the beginning of your turn any time, you should have a high degree of confidence in winning. Another strategy if scoring is kept is to minimize your losses by giving up earlier. It pays to pay attention to the cards picked up by your opponents. And if they swap four cards, you instantly know what point total they have in their hand, probably for the rest of the game. You can play defense by choosing a card of great value to an opponent who has the next turn if you are forced to choose a card (in option 3). Misdirection is possible by choosing high value cards of an unwanted suit.
Several computer versions of Schwimmen are available: