Twenty-nine is a variation of the game that is popular in North India and Bangladesh.

[1] 28 is usually played by four players in fixed partnerships, partners facing each other.

There are eight cards in each of the usual "French" suits: hearts, diamonds, clubs and spades.

Based on these four cards, players bid for the right to choose trump.

[1] Subsequent players, in counter-clockwise order, may either bid higher or pass.

The play can be divided into two phases: before and after the bidder's face down trump card (also known as 'turup') is exposed.

Based on these four cards, players bid for the right to choose trump.

Before playing a card, you may call for the bidder's face down trump to be exposed.

During the first phase, the face down trump card is not considered as belonging to the bidder's hand.

If no one calls for trump to be exposed during the first seven tricks, the game stands invalid.

Many play that if the bidder scores less than half of the call this doubles the number of game points they lose.

Shuffling card means losing the game, he may only cut once without touching the pack.

A double or redouble is indicated by flipping face up one or two cards respectively from the top of this pile.

The bidding side exposes or covers two red or black pips rather than just one.

Also in some parts of India, especially in Odisha, Bihar and Jharkhand they also play in which you can bid six points in a single game.

It's called a 'C', but this can only be implemented by the bidder if there is not a single pip displayed either black or red and the opponent has given a double.

The game is cancelled if any of the following events occur: The pair rule increases or decreases the bid value by 4 points.

If the opposing team has the pair, then the bid value increases by 4 points.

In some variations people also go for doubling or halving of the points depending on which person has the king/queen pair.

In West Bengal, a variant of 28 is played where the lowest score is 16 and maximum is 28.

If the bidder is with Single Hand Show will drop all cards undertaking to win all eight tricks.

You can show the pair of king and queen of the same colour of the trump, by doing this bidding is increased or decreased by 4 points depending on which team has shown the pair that is defender or bidding team.

A variation popular among Indian South Africans is called Thunee (various spellings).

Another rule forbids the player next to the shuffler (the first bidder) to bid, if he/she has the cards of one suite only.

[2] In this variant, every King and Queen carries a negative point bringing the total number of points down to 20 from 28 (-1 for each King and Queen in the suit) Some play that opponent can show the pair anytime after the trump is revealed and that bidder can show pair after the trump is revealed if they have taken hand before the trump was revealed.