I accidentally created a chess variant when my 8yo son asked for "Cat Mode" — has anyone else stumbled into a variant by accident?
I was building a themed chess game around King Arthur when my son suggested a mode where a cat knocks pieces off the board mid-game. I implemented it literally: after 45–60 moves, pieces start randomly disappearing from the board. Suddenly you're not just playing for checkmate — you're racing against piece attrition. Run out of enough material and you stalemate yourself. It changes your whole mid-game calculus.
The game already had an unorthodox rule: one of your pawns is secretly (or openly) the Arthur Pawn. If any non-pawn, non-king piece attacks it, Excalibur fires — the attacker is destroyed and your pawn becomes a second King on the board. Win condition becomes capturing all but one royal, then of course checkmate that royal whether it's a king or Queen Elizabeth (a promoted Arthur Pawn)
Then things got a little out of hand.
The full game now includes Chess960, Fog of War, regular online chess, a living Elo ladder with 30+ themed AI opponents, and two separate leaderboards. Play more than 10 games — online or offline — and you unlock a personal AI clone that learns your style. Guilds let chess clubs field their own collective AI built from 14 metrics of their top 5 players, and you can pit clones against each other in Clone Arena battles.
Since the game was already drenched in royalty, the cat obviously needed a title. My son suggested Cupcake, I added Duchess, and that's how Duchess Cupcake of Camelot ended up as the mascot for the whole studio now called Duchess Cupcake Games.
Anyone else accidentally invent a variant while building something else — and then completely lose control of the scope? The full game is at kingarthurchess.com or the full studio at DuchessCupcakeGames.com if you want to try either mechanic.