Spades are trump, you must beat the trick if you can, and you must make your call.
Enormously popular across Nepal, India and Bangladesh, and the game most likely to be running on a phone in South Asia. Four players, everyone for themselves, spades always trump.
A 52-card deck, aces high. Thirteen cards each, the whole deck dealt. Five rounds make a game.
After looking at your hand, each player in turn calls the number of tricks they will take, minimum one. You cannot call zero — everybody has to promise something.
The player to the dealer's left leads. Then:
You must follow suit if you can — and if you can beat the highest card played in that suit, you must. If you cannot follow suit, you must play a spade if you hold one, and it must beat any spade already played if you are able. Only when you can do neither may you discard freely.
There is very little choice in this game, which is exactly what makes the call so difficult.
Highest spade wins the trick, otherwise the highest card of the suit led.
Make your call exactly, or take more, and you score the call plus one tenth of a point for each extra trick. Call four and take six: 4.2.
Fall short and you lose the whole call. Call four and take three: minus 4.
The fractional overtricks are why calls are made conservatively — an extra trick is worth almost nothing, and a missing one is a disaster. Highest total after five rounds wins.