The Stack

A chess problem, spiced with story. A king mourns the loss of his queen after his villainous opponent sacrificed his own queen to kill her, but he still has a loyal pawn who could possibly bring her back. (I don’t think the mechanics of chess quite fit the story here, since it’s possible to promote a pawn to a queen when the original queen is still on the board. But it kind of depends on whether the identity of the queen as a character is linked to its physical piece or its notional game object, and that’s really beyond the scope of the rules of chess.)

At any rate, the story here is really just flavor — while it does get reiterated during play, it isn’t extensive and doesn’t have a profound effect. No, the game is simply a chess problem, and the input is mainly a matter of making moves in “algebraic” chess notation. It’s not a large problem, giving each side just one piece other than the king, and it’s rendered smaller by the way that the game recognizes hopeless situations and cuts them short, in some cases before I personally understood that they were hopeless. Indeed, it’s so eager to do this that for a while I got the impression that there was only one allowable move from each position.

Apparently the problem is called the Saavedra Position, and it was thought that the best you could to is force a draw until Saavedra spotted a way to avoid stalemate through a clever underpromotion. It’s unlikely that I would have thought of this on my own if the game didn’t go to such pains to suggest underpromotion as a viable approach: a conspicuous portion of the help text discusses how to notate underpromotions, there are special commands for specifying what piece to promote pawns to by default, and even the title is a pretty big hint. I think that’s the main design takeaway here: how to direct the player by making them aware of possibilities.