Anti-Cheat
Fair leaderboards matter. Every score submitted to Kuroosu goes through several layers of checks – automatically, within about a minute of the score being set, and again by our staff when something looks off.
1Replay analysis every score
The replay of every osu!standard pass (Vanilla, Relax and Autopilot) on ranked, approved, qualified and loved maps is analysed with circleguard, the same toolkit the osu! community uses to investigate cheaters:
TimewarpChecks the time between replay frames. Slowing the game down leaves frames that are too short – clear cases are restricted automatically.Relax / tap assistMeasures the unstable rate (how consistent your hits are). Inhumanly consistent tapping on Vanilla and Autopilot is flagged for review.Aim assist & botsMeasures how exactly the cursor sits on the circles compared to how hard the map is, and looks for sudden, unnatural cursor jumps. A cursor that is always in the exact middle is a bot.Tap botsHumans never press a key for exactly the same time twice. Key presses that are all the same length are flagged.Replay stealingEvery replay is compared with the other replays on the same map here and with the top plays of that map on the official osu! server, Akatsuki and Ripple – Vanilla and Relax. A replay taken from there and submitted here (also as Relax) is recognised, and clear copies are restricted automatically.2Submission checks instant
Client flagsThe osu! client reports some known cheats itself (e.g. flashlight or spinner hacks). Those lead to an immediate restriction.Tampered scoresScores whose submitted data doesn't match are rejected and the player is restricted.pp limitsEvery mode has a performance limit. Going over it requires a liveplay before the account is cleared.3Human review
Only timewarp and copied replays are 100% clear. Anything else is never banned automatically. It goes to our staff team with all the measurements, who watch the replay and decide. Staff are notified instantly, and every decision is logged. We also check for multi-accounting.
We don't publish the exact limits – that would only help cheaters stay below them. Taiko, Catch and Mania scores are covered by the submission checks, pp limits and staff review.