Troika

Troika is one of several games playable with the Katarenga board and pieces. This game is invented by the author of Katarenga.

In Troika the board starts empty. The first pawn can be placed anywhere. The pawns after the first have to be placed in such a way that they can be captured by the previous pawn (en prise).
The winner is the player who is able to make a troika – that is, a line of three pawns of your own colour in a row, whether horizontal, vertical, or diagonal. They need not be adjacent, but may be any distance apart and lying at any angle relative to the board.