The rules in one minute
Players take turns placing a stone on an empty intersection. Stones never move.
Liberties are the empty points right next to a group (up, down, left, right). Stones touching in a line share liberties.
Capture: fill a group's last liberty and it's removed. A group with one liberty left is in atari.
No suicide: you can't play where your stone would have no liberties, unless that move captures.
Ko: if you just captured one stone, your opponent can't immediately recapture in a way that repeats the board. They must play elsewhere first.
End: when both players pass in a row. Your score is your stones plus the empty points only you surround. White gets komi for moving second.
Life and death
A group is safe forever if it has two separate eyes (enclosed empty points). The opponent can't fill both, because playing into either one alone would be suicide.
A group with only one eye, or none, can eventually be surrounded and captured.
Turn on Territory to see which groups the coach thinks are dead. They get a small square.