Ranked Sudoku looks like ordinary Sudoku until you notice what's ticking in the corner. You're not solving against a blank clock — you're solving against someone else's actual solve. Here's how the pieces fit together.
Ranked matches: you vs. a replayed match
Start a ranked match and you're not just filling in a grid — you're solving the same puzzle as an earlier match, replayed back move for move. Beat that replayed match's Effective Time and you win; lose if it beats you, or if you hit 3 mistakes first. There's no live opponent watching you back — the pace and the pauses you're up against came from a real player's match, recorded and played back.
Effective Time: the number that actually decides it
Your raw solve time isn't the score. Effective Time is raw time plus 10 seconds for every mistake, so two careless mistakes cost as much as 20 seconds of actual solving. Reach 3 mistakes and your ranked match ends immediately as a loss, whatever time is left on the clock. The replayed match you're up against is scored the same way, calculated from its original attempt.
ELO: one rating, and it only moves for you
Winning a ranked match raises your ELO; losing lowers it. The replayed match you're racing carries a snapshot of its creator's rating from the moment they made that run — that's what your match is calibrated against, not their rating today. Only your own ELO changes: whoever created the match you replayed isn't affected by however many people beat, or lose to, their old solve. Your first 16 ranked matches move your rating quickly to find its level; after that it shifts more gradually, match by match. For the actual formula behind those numbers, see How We Calculate ELO.
Daily Game: the one that isn't ranked
One shared puzzle, published once a day at a difficulty picked for that date. It doesn't touch your ELO, but your solve posts to that day's leaderboard — and a good one can itself become a replayed match other players go up against later. Same mechanics, raw time and mistake penalty, just no rating on the line.
Try it before you decide
None of this requires an account first. You can play a full ranked match with no signup — create an account once you want your results to count toward a real rating and show up on the leaderboards.
What's next
The rating and the ranked matches are the foundation, not the finished product. An achievements system is next up — recognizing things ELO alone doesn't capture, like clearing your first ranked match at a given difficulty tier or stringing together a run of Daily Games. Further out, actual live matches — playing someone in real time instead of against a replay — are something we'd like to get to eventually. Nothing to announce on either front yet, but both are on the board.