Someone on Mastodon (I don’t recall who) shared a link to the Los Alamos chess variant, possibly the first bit of chess ever programmed. I was familiar with some BASIC games that implemented chess variants (such as Hexapawn in 101 BASIC Games), but this was new to me.

In 1956, to implement chess on the MANIAC I, Paul Stein and Mark Wells reduced the size of the chessboard from 8×8 to 6×6. To fit the six squares on the back row, the game removes bishops in favor of knights.

It probably would have been easier to implement by removing knights, since queens can move diagonally and that code could have been reused, whereas no other piece moves like the knight. But knights are certainly more fun to play, since they can fork pieces and can’t be blocked.

With the restricted board, Stein and Wells were able to program the game in 600 instructions, looking ahead four moves. Unfortunately, since the computer took 20 minutes to make a decision, only three games were ever played. The first game was against itself. The second game, the human player spotted it a queen, yet still won. In the third game, a lab assistant who was just taught chess the week before played and lost.

Eager to play this game myself, I hacked on an open-source JavaScript chess project to make a Los Alamos variant but didn’t get very far. It’s a lot of work to modify code you haven’t written and haven’t fully comprehended. So I abandoned that project.

Besides, many apps play chess variants. I found one that did so and had fun playing this variant. It’s much faster than regular chess. I won my first game, then lost many. Then I discovered I could undo a stupid move and ended up “cheating” by undoing bad moves. A bad habit, alas.

Over time, the play became repetitive, but it made for a nice diversion.

Turns out there is a rich history of reduced chess variants, so maybe I’ll seek out another one.

Photo credit: Los Alamos National Laboratory, as shared on Wikimedia Commons

Chess-board credit: © 2009-2026 Uray M. János, licensed under the Creative Commons.