osu! BMS Ruleset

Play BMS-family charts natively in osu!lazer

Download · Gameplay guide · Skin guide · 中文

Supports .bms, .bme, .bml, and .pms charts in single-play and double-play layouts.

_{Gameplay with the developer's custom skin}

Installation

1. Download osu.Game.Rulesets.BmsRuleset.dll from the latest release. Choose a release whose xxxx.yyy version matches your installed osu!lazer version.
2. In osu!, open Settings → General → Open osu! folder, then place the DLL in the rulesets folder. Create the folder if it does not exist.
3. Restart osu!. BMS will appear in the ruleset selector.

Importing BMS Charts

1. Open Settings → BMS → Import BMS files.
2. Navigate to your BMS folder and import a chart, the current folder, or an entire directory recursively.
3. Imported charts appear in song select.

_{BMS chart importer}

Important

Only chart data is imported into osu!'s database. Audio, images, and videos are loaded from the original BMS folder. Do not move or delete that folder after importing.

Use Clean up orphaned BMS sets in the BMS settings to remove entries whose source files are missing. You can also remove all imported BMS metadata without deleting the original files.

Highlights

Supports BPM/STOP changes, long notes, mines, random branches, scroll changes, BGA, and keysounds. Judgements use beatoraja-compatible timing windows and four selectable algorithms, with six gauge types and traditional EX score alongside osu!'s normalized score.

osu!mania Skin Support

Use an existing osu!mania skin, add a dedicated [BMS] configuration, or use the built-in skin. Supports 5-key, 7-key, and 9-key charts and their double-play layouts.

Note

BMS and osu!mania skin components may overlap, such as two hit error meters appearing together. Use the skin editor to rearrange or remove them.

See the skin system guide for configuration priority and the skin.ini reference.

Visually Editable Skin Components

Use osu!'s visual skin editor to arrange, resize, and configure the playfield, BGA, gauge, judgement display, and other components. Layouts are saved per skin without modifying the chart or its skin.ini.

_{BMS components in the visual skin editor}

See Skin Components for all components and options.

Song Preview

Song-select previews use #PREVIEW, then preview.*, or synthesize audio from the chart's BGM and keysounds when neither is available.

Disable Use dedicated preview audio in the BMS settings to always synthesize previews.

Visual Offset Calibration

Adjust when notes reach the judgement line without changing audio, judgements, or scoring. Apply suggested offsets from local plays manually or automatically in the BMS settings.

LN tail visual offset makes long notes appear shorter by advancing their visual tails. See calibration and settings for details.

Uncapped BMS Frame Rate

Enable Unlock frame rate limit in the BMS settings to remove the 1000 Hz cap on rendering, updates, and input polling during BMS gameplay. Higher GC and GPU pressure may cause stutters; disable the option if this happens.

Clear Lamps

Song select shows your best local clear lamp matching the selected mods, from No Play to Max. See lamp types and filtering rules.

Difficulty Tables

Import LR2/beatoraja difficulty tables from a URL or local JSON file to add level markers and collections. Presets include Satellite, Stella, Insane BMS, Overjoy, Scramble, and Luminous.

Table entries missing from your library also appear in song select. Attempting to play one opens its download page if the table provides a link.

_{Clear lamps and difficulty-table levels in song select}

Manage tables in the BMS settings. See the difficulty table guide for import, update, and collection options.

Course Mode

Play courses imported from difficulty tables, with course gauges and table-defined constraints. Results are saved locally and shown on course cards in song select.

Courses require all stages to be installed and cannot be paused. The next song starts automatically after 99 seconds between stages. See course rules and missing charts.

Result Screen

Open any saved score to view detailed analysis without watching its replay. This includes gauge history, note and judgement timelines, Fast/Slow distribution, hit scatter and offset graphs, and per-key timing.

_{Gauge history and timing analysis}

_{View course totals or select a song card for per-song statistics}

osu!mania 7K Conversion

Play osu!mania 7K charts as BMS: the seven lanes map to BME key columns, with scratch left empty. Note timing, holds, BPM, time signatures, offsets, and scroll-velocity changes are preserved; other key counts are not supported.

Select BMS and enable Show converts in the song select filter panel.

Documentation

Guide	Contents
Gameplay and settings	Judgements, scoring, gauges, mods, key bindings, and settings
Difficulty tables	Importing and managing LR2/beatoraja difficulty tables
Skin system	skin.ini reference, osu!mania compatibility, and editable components
BMS format support	Parser behavior, supported commands and channels, and reference links
Development	Building from source, icon generation, missing features, and known issues