One player Game... How to manage End?

[Rudolf]

Hello,
I did not find in the doc how to manage one player game End for one player game...
right now, when end arrives, player is always winner ... I've got a condition, and I would like to code at the end test, if condition not realised player loses.
How can I define the status player loses or just 'Game lost' ... is it something linked to tiebraker?

thanks.