Hit circles are coloured, circular hit objects present in both osu! and osu!taiko beatmaps. Their appearance varies between each game mode but will generally require a player to click on/tap the hit circle in time with the beat to earn score based on how accurate they were (e.g. if they clicked too early, their points would be reduced). Tapping hit circles gives a very small boost to the health bar, alongside a bigger boost at the end of a combo.
In osu!, hit circles appear with a number on top; showing their place in a combo. Hit circles are also outlined with approach circles, which shrink around them. Once the approach circle overlaps the hit circle, the player should click on/tap the hit circle to earn score.
In osu!taiko, hit circles appear from right-to-left as either red or blue notes (Don or Katu). As hit circles approach and line up with the white judgement circle the correct key(s) must be pressed to gain score.