Toepen is a fast trick-taking game for three to eight players. It is played with a 32-card pack, with the cards in each suit ranking 10 (highest), 9, 8, 7, A, K, Q, J (lowest). The basic object of each hand is to win the last trick.
The cards are dealt clockwise so that each player receives four cards.
After the deal, the undealt portion of the pack is left face-down in the middle of the table. Then any player whose hand consists entirely of As, Ks, Qs, and Js may discard her hand face downward and deal herself a new one. Indeed, any player may discard her hand face downward and deal herself a new one, but there is a risk. When a hand has been discarded in this way, it may be challenged by any other player, by turning it face upwards: if it is found to contain a 10,9,8 or 7 the discarder loses one life (but keeps her new hand) while if it really consists entirely of As,Ks,Qs and Js the challenger loses one life. Once all the cards in the pack have been dealt, it is impossible for any more hands to be dealt.
The player on dealer's left leads to the first trick. Players must follow suit if possible, otherwise they may play any card. A trick is won by the highest card of the suit led. The winner of a trick leads to the next trick.
The winner of the fourth and last trick will deal the next hand. Each of the other players loses a life or lives as described below.
At any time during a hand, once all the players have had an opportunity to pick up their cards, a player may knock by rapping the table sharply. This increases the value of the hand by one life. When a player knocks, the other players may stay in, risking losing this extra life; or may fold, losing the current stake and taking no further part in the hand.
The last player to knock may not knock again on the same hand, until someone else has knocked.
Those who stay in to the end of the hand lose one more life than the total number of knocks. So for example if there are no knocks, everyone except the winner of the last trick loses one life; if there was one knock everyone who stayed in, except for the winner of the last trick, loses two lives, and so on.
Those who fold on the first knock immediately lose one life; those who fold on the second knock lose two lives and so on - that is, by folding you lose the same amount you would have lost if the game had gone to the end with no further knocks and you lost the last trick.
If a player knocks and everyone else folds, the player left in wins that hand (losing no life) and deals the next.
If the winner of a trick folds after playing the winning card to the trick, but before the following trick has begun, the turn to lead to the next trick passes to the next player to the left who has not yet folded.
If the winner of the last trick folds, everyone will lose lives: the winner of the last trick will lose because she folded and all the others still playing will lose because they did not win the last trick. (Example: on the last trick, with no previous knocks, A leads the 
7. C knocks and A folds, believing C has a high diamond, but then B plays the 
9 and C plays the 10. A loses one life for folding and B and C each lose two lives for staying in and not winning the last trick.)
A player may not knock and fold on her own knock.
There are two ways to organise this.
When a player has lost ten lives, the game ends and this player is the loser. In the drinking game, the loser buys a round of drinks, the score is wiped clean and the next rubber starts. (In practice, this will cause drinks to arrive at an excessive rate. It might be more realistic if the loser just puts a dollar in the drinks kitty).
A player who has already lost nine lives is not allowed to knock. Similarly, a player who has already lost eight lives cannot make the second knock, one who has already lost seven lives cannot make the third knock, etc.
A player who holds three tens must whistle. A player who holds three jacks may whistle. A player who holds four tens must stand up. A player who holds four jacks may stand up. If a player is obliged to whistle but cannot, she must sing loudly. Such behaviour may encourage other players to fold, if they notice it.
Players should avoid making sounds which might be mistaken for knocks: e.g. glasses should be put down gently. Players must not whistle, sing or stand up without the requirements described above.
Beginners and intoxicated players tend to play too loosely: they knock too often, and stay in too readily when another player knocks. In a game like this, if you never knock, and fold whenever you hear a knock, you will never lose a rubber. However, if you are able to follow this advice, you have not been drinking enough to enjoy this game.
Note that a player who is allowed to knock may do so at any time. This includes knocking in the middle of a trick, or even at the end of the last trick. In the fast, drinking version of the game, a player who hears a knock and fails to fold immediately has stayed in: so you should always be ready to fold unless you expect to win the last trick.
If you are certain to win the last trick - for example another player leads a low card and you have the 10 of the suit - you should knock before revealing your 10. If the others fold you have lost nothing, and if anyone stays in it costs them an extra point. If you make a habit of this, and the other players always fold, you may also be able to profit by knocking occasionally when your card cannot win the last trick, hoping that the other players will believe you and fold.
There are two conventions which may be found useful, as they allow play to proceed without interruption while players are drinking. A player who is absent from the table attending to her own needs is dealt a hand in the usual way, but is deemed to have folded on the first knock. A player who is absent from the table so as to buy drinks for everyone loses no lives at all during her absence.
There are several local variations of the rules.
The number of lives varies. It is common to start at the target number (10 or 15) and count down, the loser being the first to reach zero.
One group of variations concern the case where a player who folds during a trick turns out to have played the card which would have won the trick. There are two alternative treatments of this position:
Some play special rules when a player has only one life left. This state is called "armoede" (poverty). Some play that in this case the stake for the game is immediately raised to two lives, as though the poor player had knocked, and the others must decide before the first lead whether to stay in or drop out for the loss of one life. After that, players are allowed to knock only if they have enough lives left to cover the raised stake, and the poor players are not allowed to knock.
Some continue the game after a player has reached 10 points and lost. The loser drops out and the others play on. When one one player remains in the game, this player is the winner.
A variation of this game, known as Siwweschrööm (with various alternative spellings), or Schröömen or Eifelpoker is played in the Eifel region of West Germany and as Tuppen in the Rhineland. The name means "seven strokes". The cards and play are essentially the same as in Dutch Toepen, without the actions to indicate three or four sevens or tens. A player who accumulates seven points drops out of the game, and the last surviving player is the winner.
Toepen rules in Dutch can be found on the Toepen Wikipedia page.
Dutch Toepen can be played on line at www.toepen.eu.
With Stephan Simons' Toepen (or Schröömen) computer game, available in English, German and Dutch, you can play against computer opponents or against live opponents over a network (for example over the Internet).
Rules and further information on Siwweschrööm can be found on several German web sites: