osu! ranking criteria

Notice: This document is an extension of the general ranking criteria.

This set of osu! ranking criteria lays out rules and guidelines that osu!-specific beatmaps must follow in order to progress through the beatmap ranking procedure.

Overall

Overall rules and guidelines apply to every kind of osu! difficulty. Rhythm-related rules and guidelines apply to approximately 180 BPM beatmaps with 4/4 time signatures. If your song is drastically faster or slower, some variables might be different, as detailed in Scaling BPM on the ranking criteria.

General

Rules

• Hit objects must never be off-screen in 4:3 aspect ratios. Hit objects that are even partially off-screen can create reading difficulties. Test play your beatmap to confirm this.
• Spinners must be long enough for Auto to achieve 1000 bonus score. Shorter spinners do not allow adequate spin time.
• Each beatmap must use at least two different custom combo colours unless the default skin is forced. The combo colours must not blend with the beatmap's background/storyboard/video in any case. This is so hit objects are always visible to the player and custom skin's combo colours do not blend with the background accidentally.
• All actively clicked parts of objects must have at least one audible hitsound that does not blend with the song. Players do not receive enough feedback otherwise. Using keysounds as hitnormals without other distinct additional hitsounds, for example, is not allowed.
• Difficulties must convert to other game modes without breaking star rating/performance points. In certain cases, a .osu file can be formatted improperly, causing converted difficulties to incorrectly display star rating and reward inaccurate performance points.
• If the drain time of each difficulty is...

  • ...lower than 3:30, the lowest difficulty cannot be harder than a Normal.
  • ...between 3:30 and 4:15, the lowest difficulty cannot be harder than a Hard.
  • ...between 4:15 and 5:00, the lowest difficulty cannot be harder than an Insane.
  • Break times may be combined with drain time to meet the above thresholds. For the highest difficulty, this is limited to at most 30 seconds of break time. This does not apply to difficulties with less than 30 seconds of drain time.

Guidelines

• Sliderends that do not represent a specific sound in the music should be snapped according to the song's beat structure. If the song is using a straight beat, 1/4, 1/8, 1/16 should be used. If the song is using a swing beat, 1/6 or 1/12 should be used. If the song has a beat in a different position from what was recommended, snapping to an actual beat always takes priority.
• All circles and slider heads should be snapped to distinct sounds in the music. Adding hit objects where there is no musical cue to justify them can result in unfitting rhythms.
• Slider tick rate should be set according to the song. For example if your song contains a section that uses 1/3 rhythms only, using tick rate 2 would not be fitting for the entire beatmap. In such cases, tick rate 1 should be used.
• Avoid using combo colours, slider borders or hitcircleoverlays with ~50 luminosity or lower. Dark colours like these impact readability of approach circles with high background dim and the other elements partially give up their functions as borders.
• Avoid using combo colours and custom slider track colours with ~220 luminosity or higher during kiai times. They create bright pulses which can be unpleasant to the eyes.
• Spinner ends, slider ends, and slider reverses should have hitsound feedback. If these are used to represent a held sound and do not align with a distinct sound, having no feedback is acceptable.
• Avoid using sound samples for sliderslide, sliderwhistle, and spinnerspin which do not naturally loop. These hitsounds are continuous, meaning that their files play from start to end and loop as one continuous sound for the length of the object, so using sound files with a clear impact for them might lead to unwanted side effects.
• Avoid unjustified difficulty spikes. Difficulty should be representative of the song's intensity.

Skinning

Rules

• Spinner circles and their centres must be clearly visible and exactly centred. This is to ensure that players have a visible aid to help them spin consistently, as well as a visual reference point to spin around.
• Hit100 and hit300 must be different from corresponding geki and katu skin elements. Hit300g, hit300k, and hit100k indicate if players perfectly hit all 300 in a combo.
• A custom slider border colour must be selected when a beatmap contains skin elements from the hit circle or slider sets. This is to avoid the default slider border or a player's custom skin's slider border from conflicting with the beatmap's specific colour scheme. This is done by adding SliderBorder: <RGB Value> under [Colours] in a .osu file.
• Slider body colour cannot be too similar to slider border colour. If both of these settings are too similar to each other, then the slider border element loses its point as a visual border for the slider. Slider body colour can be selected by adding SliderTrackOverride: <RGB Value> under [Colours] in a .osu file.
• Slider body colour and slider border colour together must not blend in with a beatmap's background or video. At that point, they make slider paths unclear or ambiguous to read. Having one blend in while the other does not may be acceptable.

Guidelines

• Usage of the new style spinners is not recommended. It can be only used with Preferred Skin set to Default. Skins using SpinnerBackground will change the colour of spinner-background.png and that could negatively change spinner's appearance. This setting does not work via editing the [Colours] column in the .osu file of the beatmap.

Difficulty-specific

Difficulty-specific rules and guidelines do only apply to the difficulty level they are listed for and therefore do not apply to every osu! difficulty. Rhythm-related rules and guidelines apply to approximately 180 BPM beatmaps. If your song is drastically faster or slower, some variables might be different, as detailed in Scaling BPM on the ranking criteria.

Difficulty names

Main article: Difficulty naming

• Easy
• Normal
• Hard
• Insane
• Expert

Easy

Rules

• Objects 1 beat apart or less must not fully overlap.
• Do not use slider reverse arrows that do not follow the visible slider path. These misrepresent the direction of a slider.
• Every slider must have a clear and visible path of movement to follow from start to end. Sliders that overlap themselves without straightforward slider borders and sliders whose individual sections are unreadable cannot be used. A slider's end position must be clear under the assumption that a player has a skin which makes slider end circles fully transparent.

Guidelines

• Time-distance equality should be used. Variations are acceptable if they are clearly different from spacing used for different rhythms. When hit objects are more than 2 beats apart and have relatively high spacing on the playfield, time-distance equality does not need to be as precise.
• When distance snap is used, try to keep it between 0.8x and 1.2x. Values too much higher or lower may make the difference between slider velocity and spacing counterintuitive. A higher distance snap can be used to avoid overlapping, but the slider velocity should be increased if you find yourself doing this often.
• Avoid slider velocity above 1.3.
• Note density should consist of mostly 1/1, 2/1, or slower rhythms.
• Avoid using sliders shorter than 1/2 of a beat. These are too fast to be comprehended by new players.
• Avoid overlapping circles, slider heads, and slider tails. These can be confusing for new players. 1/1 overlaps due to distance snapping should be avoided with higher spacing or slider velocity.
• Avoid 1/1 sliders with multiple reverses. New players are unable to read additional reverses because they are visible for such a short amount of time.
• Avoid slider-only sections. Aiming and following a lot of sliders in a row can be tiring for new players. In such cases, circles and rest moments without hit objects to click or follow should be used.
• Frequently manipulating slider velocity is discouraged. Slider velocity should only be changed for sections of music with different pacings and should not be drastically variable.
• Use straightforward and easily understandable slider shapes. New players may not understand how to follow more complex shapes.
• There should be at least 4 beats between a spinner's end and the next object. This is to ensure adequate time to click a hit object following a spinner.
• Avoid spinners less than 4 beats. Players need time to recognise that they have to begin spinning.
• Avoid fully covering slider reverse arrows with hit objects within 4 beats of the reverse arrow being reached. This gives players enough time to recognise the reverse arrow.
• Avoid fully overlapping slider bodies within 4 beats of each other. Doing so can cause sliders to be misread as a circle due to obscuring the slider body.
• Ensure that your combos are not unreasonably short or long. Combos should reflect patterns expressed in the song, such as bars of music or vocal/instrumental phrases.
• Avoid overlapping hit objects with other elements of the default and beatmap-specific skins. This refers to all elements that are part of the interface and can be skinned.

Difficulty setting guidelines

• Approach rate should be 5 or less.
• Overall difficulty / HP drain rate should be between 1 and 3.
• Circle size should be 4 or lower.

Normal

Rules

• Objects 1 beat apart or less must not fully overlap.
• Do not use slider reverse arrows that do not follow the visible slider path. These misrepresent the direction of a slider.
• Every slider must have a clear and visible path of movement to follow from start to end. Sliders that overlap themselves without straightforward slider borders and sliders whose individual sections are unreadable cannot be used. A slider's end position must be clear under the assumption that a player has a skin which makes slider end circles fully transparent.

Guidelines

• Time-distance equality should be used. Variations are acceptable if they are clearly different from spacing used for different rhythms. When hit objects are more than 1 beat apart and have relatively high spacing on the playfield, time-distance equality does not need to be as precise.
• When distance snap is used, try to keep it between 0.8x and 1.3x. Values too much higher or lower may make the difference between slider velocity and spacing counterintuitive. A higher distance snap can be used to avoid overlapping, but the slider velocity should be increased if you find yourself doing this often.
• Note density should consist of mostly 1/1, occasional 1/2, or slower rhythms.
• Avoid overlapping circles, slider heads, and slider tails. These can be confusing for new players. 1/2 overlaps due to distance snapping are an exception.
• Avoid long chains of hit objects with 1/2 gaps. Too many consecutive hit objects overlapping can be confusing for new players.
• Avoid 1/2 sliders with multiple reverses. New players are unable to read additional reverses because they are visible for such a short amount of time.
• Avoid slider-only sections. Aiming and following a lot of sliders in a row can be tiring for new players. In such cases, circles and rest moments without hit objects to click or follow should be used.
• Stacks are acceptable, but avoid switching between 1/1 and 1/2 stacks repeatedly. This may cause reading issues for new players, since two different rhythms are visually the same.
• Frequently manipulating slider velocity is discouraged. Slider velocity should only be changed for sections of music with different pacings and should not be drastically variable.
• Use straightforward and easily understandable slider shapes. New players may not understand how to follow more complex shapes.
• There should be at least 2 beats between a spinner's end and the next object. This is to ensure adequate time to click a hit object following a spinner.
• Avoid spinners less than 3 beats. Players need time to recognise that they have to begin spinning.
• Avoid fully covering slider reverse arrows with hit objects within 3 beats of the reverse arrow being reached. This gives players enough time to recognise the reverse arrow.
• Avoid fully overlapping slider bodies within 3 beats of each other. Doing so can cause sliders to be misread as a circle due to obscuring the slider body.
• Ensure that your combos are not unreasonably short or long. Combos should reflect patterns expressed in the song, such as bars of music or vocal/instrumental phrases.
• Avoid overlapping hit objects with other elements of the default and beatmap-specific skins. This refers to all elements that are part of the interface and can be skinned.

If a Normal difficulty is required and used as the lowest difficulty of a beatmap, it should also follow these guidelines:

• Avoid more than three actively clicked 1/2 rhythms in a row.
• Include a 1/1 or longer gap in rhythm for every two measures of gameplay. Leniency is permitted for sections of beatmaps with extremely long sliders, such as sliders longer than 2 measures.
• Avoid more than four consecutive 1/2 sliders. This includes 1/2 reversing sliders.
• Objects making up actively clicked 1/2 rhythms should overlap each other on the playfield. Passively played 1/2 rhythms that do not overlap, such a sliderend followed by a circle, are acceptable.
• Avoid slider velocity above 1.3.

Difficulty setting guidelines

• Approach rate should be between 4 and 6.
• Overall difficulty / HP drain rate should be between 3 and 5.
• Circle size should be 5 or lower.

Hard

Rules

• Objects 1/2 of a beat apart or less must not fully overlap. Slider heads or tails fully overlapped by slider tails are exempt, so long as their sliderbodies are visible.
• Do not use slider reverse arrows that do not follow the visible slider path. These misrepresent the direction of a slider.
• Every slider must have a clear and visible path of movement to follow from start to end. Sliders that overlap themselves without straightforward slider borders and sliders whose individual sections are unreadable cannot be used. A slider's end position must be clear under the assumption that a player has a skin which makes slider end circles fully transparent.

  • Ambiguous sliders with follow circles that cover the whole slider path are allowed, assuming the slider borders are straightforward.

Guidelines

• There should be at least 1 beat between a spinner's end and the next object. This is to ensure adequate time to click a hit object following a spinner.
• Note density should consist of mostly 1/2, occasional 1/4, or slower rhythms.
• Avoid streams made of more than 5 notes. Short reversing sliders can be used in exchange for these when the song supports it.
• Avoid visually similar spacing for different rhythms. Spacing variation through jumps on points of emphasis are encouraged, but only if these jumps are recognisably different from other rhythm gaps.
• Slider tick hitsounds are discouraged. If you want to use them, then make sure that their volume is balanced (i.e. notably quieter than regular hitsounds). A very loud slider tick, especially when only used once or twice, can be extremely jarring.
• Avoid spinners less than 2 beats. Players need time to recognise that they have to begin spinning.
• Avoid fully covering slider reverse arrows with hit objects within 2 beats of the reverse arrow being reached. This gives players enough time to recognise the reverse arrow.
• Avoid fully overlapping slider bodies within 2 beats of each other. Doing so can cause sliders to be misread as a circle due to obscuring the slider body.

Difficulty setting guidelines

• Approach rate should be between 6 and 8.
• Overall difficulty should be between 5 and 7.
• HP drain rate should be between 4 and 6.
• Circle size should be 6 or lower.

Insane

Rules

• Every slider must have a clear and visible path of movement to follow from start to end. Sliders that overlap themselves without straightforward slider borders and sliders whose individual sections are unreadable cannot be used. A slider's end position must be clear under the assumption that a player has a skin which makes slider end circles fully transparent.

  • Ambiguous sliders with follow circles that cover the whole slider path are allowed, assuming the slider borders are straightforward.

Guidelines

• Objects 1/4 of a beat apart or less should not fully overlap, especially on simpler Insane difficulties.
• Avoid slider reverse arrows that do not follow the visible slider path. These misrepresent the direction of a slider.
• Avoid cross screen jumps and streams whose circles do not overlap. These are beatmapping techniques primarily reserved for Expert level difficulties.
• Slider tick hitsounds are discouraged. If you want to use them, then make sure that their volume is balanced (i.e. notably quieter than regular hitsounds). A very loud slider tick, especially when only used once or twice, can be extremely jarring.
• Avoid fully covering slider reverse arrows with circles, slider heads, or slider tails within a 1/2 beat of the reverse arrow being reached. This gives players enough time to recognise the reverse arrow.
• Avoid fully overlapping slider bodies within a 1/2 beat of each other. Doing so can cause sliders to be misread as a circle due to obscuring the slider body.

Difficulty setting guidelines

• Approach rate should be between 7 and 9.3.
• Overall difficulty should be between 7 and 9.
• HP drain rate should be between 5 and 8.
• Circle size should be 7 or lower.

Expert

Rules

• Every slider must have a clear and visible path of movement to follow from start to end. Sliders that overlap themselves without straightforward slider borders and sliders whose individual sections are unreadable cannot be used. A slider's end position must be clear under the assumption that a player has a skin which makes slider end circles fully transparent.

  • The slider path is allowed to be ambiguous if the cursor can stay inside the slider's follow circle without any movement away from the slider head.

Guidelines

• Avoid slider reverse arrows that do not follow the visible slider path. These misrepresent the direction of a slider.
• Slider tick hitsounds are discouraged. If you want to use them, then make sure that their volume is balanced (i.e. notably quieter than regular hitsounds). A very loud slider tick, especially when only used once or twice, can be extremely jarring.

Difficulty setting guidelines

• Approach rate / Overall difficulty should be 8 or higher.
• HP drain rate should be 5 or higher.
• Circle size should be 7 or lower.