The osu! Ranking Criteria is a set of rules and guidelines that apply to the creation of osu!-specific difficulties. In order to get an osu!-specific difficulty ranked, it is mandatory that the creation obeys to the listed criteria. While all rules must be followed in any circumstance, guidelines may be violated under exceptional circumstances. These exceptional circumstances must be warranted by an exhaustive explanation as of why the guideline has been violated and why not violating it will interfere with the overall quality of the creation.

Rule proposals as well as suggestions are discussed in the Ranking Criteria Subforum. Any rule that went through a discussion and community approval process is listed here as it has been agreed on in the respective discussion thread.

Glossary

Difficulty Names

  • Easy Easy
  • Normal Normal
  • Hard Hard
  • Insane Insane
  • Expert Expert

Refer to this thread for alternative difficulty naming methods.

  • Hard Advanced: A difficulty combining elements found in both Normal and Hard difficulties. It is often used to fill the gap between lower-level normals and higher-level hards.
  • Expert Extra/Extreme/Ultra: Names used to replace Expert and to indicate increasing difficulty among multiple Expert difficulties.

Gameplay

  • Jump: Hit objects spaced further apart from each other in comparison to the average spacing for such patterns. Usually snapped to 1/2 beats.
  • Stream: Consecutive circles grouped together. Usually snapped to 1/4 beats.
  • Stack: Two or more hit objects in the same grid location whose placements are automatically offset.
  • Stack leniency: A setting used to determine if hit objects stack or perfectly overlap each other. Increasing its value will cause hit objects to stack at longer time intervals.
  • Overlap: Hit objects touching each other where they do not stack.
  • Perfect overlap: Hit objects in the same grid location that do not stack.
  • Snapping: Timeline tick where an object is placed.
  • Slider head/tail: The start/end positions of a slider.
  • Slider border: Visible outline of a slider's path. When this is distorted through overlaps, sliders can become harder to read.
  • Slider anchors: Tools used to shape the body of a slider. Gray anchors shape a single curve, while red anchors end the current curve. Also referred to as "nodes".
  • Slider velocity: A slider's speed defines how much space it travels within a given beat. Base slider velocity can be controlled in the timing panel and additional changes can be made through inherited (green) timing points.
  • Buzz slider: A slider snapped to 1/8 or denser with more than three reverses, causing a "buzz" rather than individual hit sounds.
  • Short reversing slider: A short slider (usually 1/4 or 1/8 snapping) with 1 or more reverses. This allows a player to keep their cursor in one place while the slider reverses.
  • Hold slider: A slider requiring the player to keep their cursor in one place rather than follow the sliderball.
  • Burai slider: A slider directly overlapping its own body, resulting in an unclear slider path.
  • Extended slider: A slider whose tail is not snapped to a specific beat in the music, but is instead expressing a prolonged sound. The most common extended slider is 3/4 of a beat.
  • Slider tick rate: The amount of slider ticks that appear per beat of music.
  • Spinner recovery time: The time between the end of a spinner and the following hit object.
  • Time-distance equality: Spacing between hit objects is proportional to the duration of time between them. Also known as using a constant distance spacing.
  • Hit object/Note density: The average timeline gaps between hit objects expressed in fractions of a beat (such as 1/1 for one beat, 1/2 for half a beat).
  • Keysounding: hit sounding using samples extremely similar or directly from the song in their respective places. This method of hit sounding usually provides low feedback to the player.

Overall

Overall rules and guidelines apply to every kind of osu! difficulty. Rhythm related 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 this article.

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. Short spinners are unreasonably difficult to complete.
  • 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.
  • Every slider must have a clear and visible path to follow from start to end. Sliders which overlap themselves in a way that makes any or their individual sections unreadable or ambiguous cannot be used, such as burai sliders and hold sliders without straightforward slider borders.
  • Do not use keysounds without hitnormal support. If sounds blend perfectly with the song, feedback for hitting notes is minimal.

Guidelines

  • You should not silence both slider ticks and slider slides together. Silencing both can be fitting when ticks cover no sounds, but doing so otherwise is not acceptable.
  • Avoid visually obstructing reverse arrows on sliders with other hit objects in the default or beatmap-specific skin. Covering up reverse arrows on sliders can result in sliders being ambiguous to read.
  • Sliderends of extended sliders 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.
  • Avoid perfectly overlapping slider bodies in a way that causes reading issues. Doing so can cause sliders to be misread as a circle due to obscuring the slider body.
  • 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 snapping 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 low background dim and the other elements partially give up their functions as borders.
  • Avoid using combo colours with ~220 luminosity or higher during kiai times. They create bright pulses which can be unpleasant to the eyes.
  • 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.
  • 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.
  • Buzz sliders should have appropriate delay before the next note. 1/8 and 1/16 sliders should be followed by a 1/4 gap, whereas 1/12 sliders should be followed by a 1/6 gap. This ensures that the hit-window between hit objects is playable.
  • Spinners should be used when they fit the music. This is to ensure score differences among perfect plays on the leaderboard. They usually fit during held notes, changes in intensity, or transitions between sections.
  • Avoid using similar combo colours in successive combos. Players should be able to differentiate between different combos in a beatmap.
  • Spinner ends, slider ends, and slider reverses should have hit sound 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 hit sounds 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 replacing the hit finish in soft/normal samplesets with frequently used custom hit sound samples. Using these finishes to represent snare/bass drums or a song's melody can sound obnoxious for anyone disabling beatmap hit sounds. Replacing hit whistles/claps is recommended because those samples are used more often.

Skinning

Rules

  • Spinner circles and their centers must be clearly visible and exactly centered. 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 guidelines apply to approximately 180 BPM beatmaps. If your song is drastically faster or slower, some variables might be different. Apply reasonable judgement in these cases.

Easy Easy

Rules

  • Objects 1 beat apart or less must not overlap perfectly.

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.
  • 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.
  • 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.
  • Spinner recovery time should be at least 4 beats. This is to ensure adequate time to click a hit object following a spinner.
  • Avoid spinners less than 4 beats. Players need time to recognize that they have to begin spinning.

Difficulty Setting Guidelines

  • Approach Rate should be 5 or less.
  • Overall Difficulty / HP Drain Rate should be between 1 and 3.

Normal Normal

Rules

  • Objects 1 beat apart or less must not overlap perfectly.

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 hit objects after sliders which appear underneath the previous slider's path. Players at this level fully follow sliders’ paths, so placing a hit object directly after the slider is more intuitive. This also includes stacks underneath slider ends.
  • 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.
  • 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.
  • Spinner recovery time should be at least 2 beats. This is to ensure adequate time to click a hit object following a spinner.
  • Avoid spinners less than 3 beats. Players need time to recognize that they have to begin spinning.

If you use a Normal difficulty as the lowest difficulty of your beatmapset, it should follow these guidelines in addition to the ones above

  • 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 1.3x.

Difficulty Setting Guidelines

  • Approach Rate should be between 4 and 6.
  • Overall Difficulty / HP Drain Rate should be between 3 and 5.

Hard Hard

Rules

  • Objects 1/2 of a beat apart or less must not overlap perfectly. Slider heads or tails perfectly overlapped by slider tails are exempt, so long as their sliderbodies are visible.

Guidelines

  • Spinner recovery time should be at least 1 beat. 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 1/2 and 1/1 spacing. Spacing variation through jumps on points of emphasis are encouraged, but only if these jumps are recognizably different from 1/1 gaps.
  • Avoid mixing 1/2 and 1/4 rhythms in the same stack. Different rhythms of this density without spacing indication can cause reading issues.
  • Slider tick hit sounds are discouraged. If you want to use them, then make sure that their volume is balanced (i.e. notably quieter than regular hit sounds). 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 recognize that they have to begin spinning.

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.

Insane Insane

Guidelines

  • Objects 1/4 of a beat apart or less should not overlap perfectly, especially on simpler Insane difficulties.
  • Avoid cross screen jumps and spaced streams. These are beatmapping techniques primarily reserved for Expert level difficulties.
  • Avoid unjustified spikes in difficulty. Difficulty should be representative of the song's intensity.
  • Slider tick hit sounds are discouraged. If you want to use them, then make sure that their volume is balanced (i.e. notably quieter than regular hit sounds). A very loud slider tick, especially when only used once or twice, can be extremely jarring.

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.

Expert Expert

Guidelines

  • Avoid unjustified spikes in difficulty. Difficulty should be representative of the song's intensity.
  • Slider tick hit sounds are discouraged. If you want to use them, then make sure that their volume is balanced (i.e. notably quieter than regular hit sounds). 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.