Ch. 36 · Glossary — osu! Codex

36 Glossary

Term	Meaning
1/4, 1/2	Note spacing relative to the beat. 1/4 notes are streams; 1/2 notes are singletaps at half the rate
Alt (alternating)	Tapping two keys in turn, one note each; the basis of streaming
AR	Approach rate: how long objects are visible before they must be hit
Burst / stream / deathstream	Runs of 1/4 notes: roughly 5 to 8, 9 or more, and long enough that stamina dominates
CS	Circle size: larger CS means smaller circles
Derust	Regaining skill after a break
Digits	Rank bracket shorthand: 6-digit is ranks 100,000 and above, 4-digit is 1,000 to 9,999, and so on
Farm map	A map whose pp is high relative to its difficulty, usually short with a spike of jumps
FC	Full combo: no misses and no broken sliders
Finger lock	Fingers seizing or refusing to alternate, usually from mashing bursts
Flow aim / snap aim	Smooth continuous movement versus sharp point-to-point movement
HP	Drain rate: how fast the health bar empties
Lazer / stable	The new client and the classic client
Mindblock	Playing a pattern from memory instead of reading it, so it falls apart
Muscle memory	In players' usage, the automaticity that comes from motor learning. Physiologically the term means something else entirely (structural changes in muscle fibres that speed re-training after a layoff), and the gaming usage misleads: what you build is adaptable motor control, not a memorized distance (Ch. 17)
Notelock	Being unable to hit an object because a previous object's hit window is still open
OD	Overall difficulty: how tight the timing windows are
One-trick	Playing one skill set or mod almost exclusively
osu!pixel	The game's internal coordinate unit; circle sizes are measured in it
pp	Performance points: the score-weighted ranking currency
Practice difficulty	A copy of a map, usually cut short in the editor, made to drill one section
Singletap	Hitting consecutive notes with one finger
Sightread	Playing a map correctly the first time you see it
SS	A perfect-accuracy score (100%)
Star rating	The game's difficulty number for a map
TV size	A map of a roughly 90-second TV-edit song
UR	Unstable rate: the standard deviation of your hit errors, times 10

Finished this chapter?

Mark it complete for 🍪 100 and track your way to Codex Graduate.

Community discussion

Discussion is not evidence: it never changes the chapter directly. Corrections go through Codex suggestions, where they're checked against sources.

Forum threads about this chapterStart one

None yet — longer questions and write-ups belong in the forums, where they stay findable.

36 Glossary

Term	Meaning
1/4, 1/2	Note spacing relative to the beat. 1/4 notes are streams; 1/2 notes are singletaps at half the rate
Alt (alternating)	Tapping two keys in turn, one note each; the basis of streaming
AR	Approach rate: how long objects are visible before they must be hit
Burst / stream / deathstream	Runs of 1/4 notes: roughly 5 to 8, 9 or more, and long enough that stamina dominates
CS	Circle size: larger CS means smaller circles
Derust	Regaining skill after a break
Digits	Rank bracket shorthand: 6-digit is ranks 100,000 and above, 4-digit is 1,000 to 9,999, and so on
Farm map	A map whose pp is high relative to its difficulty, usually short with a spike of jumps
FC	Full combo: no misses and no broken sliders
Finger lock	Fingers seizing or refusing to alternate, usually from mashing bursts
Flow aim / snap aim	Smooth continuous movement versus sharp point-to-point movement
HP	Drain rate: how fast the health bar empties
Lazer / stable	The new client and the classic client
Mindblock	Playing a pattern from memory instead of reading it, so it falls apart
Muscle memory	In players' usage, the automaticity that comes from motor learning. Physiologically the term means something else entirely (structural changes in muscle fibres that speed re-training after a layoff), and the gaming usage misleads: what you build is adaptable motor control, not a memorized distance (Ch. 17)
Notelock	Being unable to hit an object because a previous object's hit window is still open
OD	Overall difficulty: how tight the timing windows are
One-trick	Playing one skill set or mod almost exclusively
osu!pixel	The game's internal coordinate unit; circle sizes are measured in it
pp	Performance points: the score-weighted ranking currency
Practice difficulty	A copy of a map, usually cut short in the editor, made to drill one section
Singletap	Hitting consecutive notes with one finger
Sightread	Playing a map correctly the first time you see it
SS	A perfect-accuracy score (100%)
Star rating	The game's difficulty number for a map
TV size	A map of a roughly 90-second TV-edit song
UR	Unstable rate: the standard deviation of your hit errors, times 10

Finished this chapter?

Mark it complete for 🍪 100 and track your way to Codex Graduate.

Community discussion

Discussion is not evidence: it never changes the chapter directly. Corrections go through Codex suggestions, where they're checked against sources.

Forum threads about this chapterStart one

None yet — longer questions and write-ups belong in the forums, where they stay findable.