Mentioned in TFA: This version of chess is given by Martin Gardner in his "Mathematical Games" column of July 1980 (pages 27 and 31) — https://www.jstor.org/stable/24966361 — and the analysis of White's mate is given in the column of August 1980 (page 18) — https://www.jstor.org/stable/24966383.

I do wonder how things would change if the board were 9 cells long; 10 cells long; etc. Also, it seems "in the spirit" to permit castling if neither K nor R has moved yet: i.e., from the position

K _ R N r _ n k

White ought to be permitted to

_ R K N r _ n k

(Or maybe there's a stronger argument for R K _ N r _ n k, actually. The former was conceptually "rook moves halfway toward king, then king moves to the other side of rook"; but the latter is "rook moves two steps in king's direction while king moves to the other side of rook.")

I'm pretty sure this wouldn't change the analysis on the 8-cell board at all, though. I wonder if it would change the analysis on any size of board.

Reminds me of Edwin A. Abbott's Flatland, where he describes Lineland. A one-dimensional world whose King can only move forward and backward, cannot conceive of sideways, and considers his tiny segment of existence complete and sufficient. The Linelanders are portrayed as pitiable, intellectually imprisoned by their single dimension. Much like us in our three :)

This is really nice.

Incidentally, there is an actual 1D game that is one of the most popular games on the planet: Backgammon.

It was a lot more fun than I first thought!

Haha, i was taking N4 and N6, but didn’t figure the steps after that.

To win we need to let knight die because rook can move multiple steps to kill the king.

From a third person perspective R2 is a deceptive move that takes advantage algorithm to make the black king back off to kill its knight.

It's very interesting and fun!)

I was only able to beat this after a couple retries. The hint was hard to read.

Oh very interesting. Even with these restrictions, there are quite a few variations, and it seems only one ends up with white winning.

It took me an embarrassing number of attempts to win.

Finally, a version of Chess I can understand. Thank you.

i could not beat it, and i can't read that chess notation

Cool idea. This is smart and lean. I like it

Nice! :)

Fun stuff, love it!

The first move is always: white rook takes black rook, then the only remaining move for black is to move the knight away, which results in checkmate.