You should now know what the ko rule (See Rules of Go) is but you might be wondering how you should handle a ko if it comes up.
Don’t worry if you don’t get it straight away, kos are notoriously tricky, even for dan players.
Also, I recommend you play along with this to get a good feel for it, either on your own board or a Go program.
In this game, white has invaded black’s corner in the lower-left.
Usually the result of this invasion is a ko. That is, black can only kill this stone by winning the ko fight.