No Turns, No Locking Each Other Out: How Co-op Sudoku Stays in Sync
Everyone in the room can fill any open cell, at any time — here's how the shared grid stays consistent without turn order.
Blog
Blog
Notes on building Grandmaster Sudoku, and puzzle strategy along the way.
Under the hood
Play together
Team Battle: The Icebreaker Your Standup Didn't Know It Needed
No app to install, no accounts to create — just a room code, two to four teams, and a shared grid to fight over.
Under the hood
How a Grandmaster Sudoku Race Actually Works
Six players, one grid, no puzzle data sent over the network. Here's the trick.
Strategy
Killer Cages, Explained: The Sudoku Variant That's Secretly Just Algebra
No starting numbers, just cage sums. Here's how to read one without wanting to throw your phone.
Behind the scenes
Designing a Sudoku a Grandmaster Wouldn't Be Bored By
Why one very hard grid wasn't the goal — six different ways to be hard was.