What if a chessboard had no edges?

That question became the most fun thing I have built this year. I just shipped “Endless” mode in Chess: Knight Fever, which is chess played on a Möbius strip, and in the newest update you can play it against a friend over Wi-Fi.

Here is the idea. Take a normal 8x8 board and glue the a-file to the h-file, but with a half-twist, the way a Möbius strip joins its ends. Now the board has no left or right edge. A rook that slides off one side reappears on the other, flipped to the opposite rank. Bishops bend across the seam. Even the opening position has legal captures that wrap around the board. It is still chess, with every normal rule, but your intuition has to relearn the geometry.

The hard part was making the engine agree with that geometry. Bending a board in software is messy, so instead of bending it I doubled it. The game runs on a flat 16-wide cylinder that projects down onto the 8x8 board with the half-twist baked in. That keeps move generation, check, and checkmate correct for every piece without special-casing the seam.

A short tour of the last two updates.

1.1.0

Endless (Möbius) mode for solo play and pass-and-play, with a draggable 3-D view of the strip
Two piece sets (a chunky original and a clean classic) and seven board color themes
An on-device assistant and an optional move coach that run fully offline
A dedicated Running Matches screen and steadier iCloud sync

1.1.1

Endless over Wi-Fi: host a local match, choose Endless, and both players are on the twisted board live, move for move
Refreshed game-setup controls that look consistent across iPhone, iPad, and Mac
Connection and stability polish

A few principles I held onto throughout. It is free, there are no accounts, and your games stay on your device and in your own iCloud. Voice and accessibility features are free as well, never behind a paywall. One codebase runs on iPhone, iPad, Mac, and Apple Vision Pro.

If you play chess, or you just want to watch your sense of a chessboard turn inside out, I would love for you to try Endless and tell me what breaks your brain first.

Chess: Knight Fever is on the App Store.