Lobsters: What the fox say?

Hmm I was hoping there was a link to play the game against the computer. But the only link to a playable version seems to be https://xkqr.org/fox-game-puzzles/ which presents pre-arranged game states as puzzles to solve.

Excellent read nonetheless. I like how the asymmetry makes it a good game to play with kids.

Unfortunately I only have a debugging interface for playing against the computer in the terminal. It wouldn't be too hard to get something on the web, though, I just didn't expect there to be any interest. I'll see if I can take the time.

I think some of the puzzles are buggy? In the sense that you are told to eat a sheep, but the check is for a specific fox to eat a sheep…

The puzzles certainly have been buggy in the past, but I haven't found any actual bugs in a good while. Any time I run across something I think is a bug now, it's just because I didn't read the situation out fully.

The check is never for a specific fox to eat a sheep. If the puzzle doesn't accept a solution using one of the foxes, it is because doing so would have one of the following consequences:

The sheep can then fill the pen and win;
The fox can be trapped; or
The solution doesn't actually lead to eating a sheep at all, because all sheep can survive a few turns.

One such situation is when one of the foxes occupies the last non-sheep point in the pen. Often the sheep can fill that location quickly once the fox moves away from it, so that fox must not move.

The next time you find a buggy solution, it would be helpful if you sent the id of that puzzle so I can check!

It is true that the wrong solution in 798be409 allows sheep to trap one fox in one move, but then the planning horizon is not clear from the text on the page… Maybe reword it as «eat a sheep within X moves without losing a fox or leaving a one-move win to sheep»?

ETA: 8048ba2b has one solution that does not instantly lose, and it says that tree search prefers d3-c3 in a real game. But am I right that the situation after the solution is still a forced win for foxes by moving the bottom fox left until it is possible to move up?

PS. I guess it would be nice to know how to load a puzzle by ID…