What is "batoo"

Batoo is a Korean variant of the board game Go. The name stems from a combination of the Korean words baduk (“Go”) and juntoo (“battle”). It is played entirely in cyberspace, and differs from Go in a number of ways, most noticeably in the way in which certain areas of the board are worth different point values. The other principal difference is that both players place three stones before the game begins, and may also place a special “hidden stone”, which affects the board as a regular stone but is invisible to the opponent. It was launched in November 2008.