The only thing I would add to
bitter_engineer's write up are the following variations:
Called Suit:
In games where the
picker has a
partner, that partner could, instead of being the person
Jack of Diamonds, could be the person with the Ace of the called suit. When someone picks, and after they bury, they call a suit, but they must have a
fail card in that suit and not the Ace, (i.e. King, 10, 9, 8, or 7). Or they can state they would like to go it alone. Now the first time the called suit is played, the partner must play the Ace. Often the strategy in these games for the picker and partner is run through as much trump as possible before the called suit is played. Most likely someone against the picker and partner will have a void in that suit, and so this is a chance for the opposition to get at least 11 points (from the ace), by trumping. (The picker has to have a fail card, 'cause he called the suit, and the partner has to have the ace). So the strategy on the opposition's side is to play the picked suit as soon as posible. Of course table talk is still prohibited, so nobody except the partner knows who the partner is, until the called suit is played.
Also you play that the picker has a partner in a four person game as well.