How do you lose a game of solitaire?

You lose a game of solitaire when you can't make any more moves. This happens when:

* You run out of cards in the stock pile. This means you've exhausted all the cards and haven't managed to build up all the foundations to King.

* You can't move any more cards. This could be because there are no cards left in the tableau that can be moved onto the foundations or waste pile, and you've exhausted all possible moves.

Essentially, you lose when you reach a point where there are no legal moves left, and you haven't completed all the foundations.

Remember, there are different versions of solitaire with varying rules, so the specifics of how to lose might differ slightly.