What is an open challenge?
An open challenge is a request for a game that hasn't been accepted yet. You can see open challenges by hovering over 'Play' on the left menu and clicking on 'New Game'
Then choose 'Custom Game' from the menu, and then click on the 'Open Challenges' tab:
This will show a graph of open games looking for opponents, and the type of game they want to play. The Icon is different depending on what kind of game it is, you can see the legend below the graph to see what each meaning is.
Click on one of the Icons to open the game challenge
This will take you to the game screen, where you can see further details about the game and the player, and decide whether to accept or not:
Here you can see the members record, whether you've played them before, their timeouts and average move speed and more.
You can use all this information to decide if you want to accept the challenge! But choose quickly, these challenges get accepted fast!
If you see the above message, this means someone else accepted the game while you were looking at it!