Katrominoes is one of several games playable with the Katarenga board and pieces. This game is invented by the author of Katarenga. In Katrominoes players in turn place pentominoes on the Katarenga board. Each player "owns" two colours, trying to cover up as many of the squares beloning to the opponent while leaving a greater number of their own uncovered. Score is calculated by multiplying the number of one of your colours still visible by the number of those of your other colour.