A star knock-out or star finish, abbreviated as star KO, is a type of KO. When characters are knocked beyond the upper blast line (save for a few exceptions, see below), they fly through the background, away from the stage, yell/scream/etc., and eventually disappear as a star (there is a random chance of a screen KO instead, where characters hit the camera, which is rarer). This takes the longest duration out of any KOs.
Any conditions on the characters are seen in the Star KO, such as if the characters are KO'd while frozen or has a Smash Ball when they are KO'd. In Flat Zone 2 and Hanenbow, conditions are not aligned with the character (i.e. the frozen block and character fly off separately).
Giant/tiny characters who are star KO'd remain giant/tiny while falling on the background (their "falling voice" remains deep/tiny as well). On the other hand, star KO'd metal characters appear in normal conditions on the background (including their voice). The only exceptions are the Metal opponents in Melee's 1 Player modes. In Super Smash Bros. Brawl, when giant/tiny characters gets star KO'd, they will return to normal size, unless the characters are playing in Giant Brawl.
Members of a computer team, such as the Fighting Wire Frames and Fighting Alloy Team, do not experience star KOs, instead undergoing the usual colorful explosion (with the exception of the oversized Wire Frames that appear in Event Match 37). Team battles in the Classic Mode and Adventure Mode also feature playable characters that cannot be Star or Screen KO'd. In Super Smash Bros., members of a team (such as the Fighting Polygon Team) can be Star KO'd. Common enemies in the Subspace Emissary mode cannot be Star or Screen KO'd (with the exception of playable characters).
- Star KO: Star KO an opponent. (10000 points in SSB, x300 points in Melee)
- Solar being: Get star KO'd. (800 points in Melee)
- Shooting Star: Finishing the match while getting star KO'd . (1500 points in Melee)
- If Kirby has copied another character's abilities and gets star KO'd, he will appear as a normal Kirby while disappearing into the background. An exception is Super Smash Bros., where he keeps his ability.
- If the opponent sent upward touches a Starman and gets star KO'd, the opponent will appear as a invincible character while disappearing into the background.
- While it is generally impossible to self-destruct as a star KO, there are a few ways: one can stand on a platform above the upper blast line or get launched upwards by Pikachu's Quick Attack in the highest platform of Hyrule Castle, Wario's fully charged Wario Waft, be carried by the Landmaster tank,Sonic's Spring Jump (works sometimes), or Jigglypuff's shield jump.