Custom rulesets

Custom osu!lazer rulesets from rulesets.info (sentakki, tau, Rush!, ...) can have their own leaderboards and rankings, by score (there's no pp for them). Staff choose which ones count.

How it works

1. Staff turn a ruleset on in the website's admin panel, Custom rulesets (admins). The page lists rulesets.info's rulesets. Turning one on pins its release as it is now: a GitHub "latest" link is resolved to the release it points at, and the DLL's address, SHA-256 and size are kept (tomyum_custom_rulesets). Each gets the ruleset id its scores are stored with: 10 and up (sentakki, tau, Rush!, hishigata and soyokaze keep the ids 10-14 other servers use).
2. Players install it from the client's settings (TumThai: Settings > General > Custom rulesets), which downloads exactly the pinned file, or put the DLL in the client's rulesets folder themselves. GET /api/v2/tomyum/rulesets (signed in) lists the rulesets turned on, with their files.
3. A play submits only on the pinned file. The client sends the ruleset's id and its DLL's SHA-256 with the score token (ruleset_hash); anything else is refused with "update it in Settings". Plays are on osu! maps (custom rulesets convert them). The score is the website's own (scores.ruleset_id 10 and up): its mods are kept as the client sent them, a play with an automation mod (Autoplay, Cinema, Relax, Autopilot) isn't ranked, and the usual play-length check applies.
4. Leaderboards: GET /beatmaps/{id}/scores?mode=<slug> gives each player's best by score (global, country, friends, team), for lazer and for the beatmap page, which has an Other rulesets… dropdown on osu! maps.
5. Rankings: /rankings/rulesets/{slug} ranks players by ranked score (their best on each ranked map, added up), worldwide or in one country. The rankings' mode selector has a … menu for them.

When the author releases a new version, Pin again moves to it and players update from the client's settings. Turning a ruleset off stops new plays submitting; its scores stay.

For plugins

IRulesetRegistry lists the rulesets turned on and names any ruleset. ScoreProcessedEvent comes for their scores too, with RulesetId 10 and up. ppy's score processor leaves them alone ("Unsupported ruleset"), and TomYum's own first places and rank #1 announcements stay with osu!'s four rulesets.

Not (yet) supported

osu!(stable) can't play them (its mode is one byte, 0-3), and there's no multiplayer, spectating, replays or pp for them. Profiles don't have tabs for them yet.