Slitherine

Hi:

Yesterday when I got access granted I set up a pbem game. I selected the France scenario and decided to play the frenchies. Today I saw the challenge was accepted by KageToraUK
Now if when I select the game I have to options, one is play if I hit this nothing happens, and the other is claim, not very sure what "attempt to claim this game?" means.
Can anybody enlighten me here?

Thanks

Oops seems like my ooponent hasn't done the turn yet. But the claim attempt question still remains, I don't get it.