How to withdraw a challenge

To withdraw a challenge you can click the OPEN icon in the Main Toolbar:

When OPEN, people can challenge you.

When CLOSED, you cannot be challenged. All challenges will also be removed.

Advanced

You can also use the command line interface and enter the server command open.

See Also:
Finding an opponent
How to seek a game
Starting your assigned tournament game
Finding an opponent
Window Options
match - command line help