An instant KO is a type of KO which occurs instantaneously and in-place, without the fighter passing a blast line or being launched at all. A character suffering an instant KO will disappear into a colorful starburst explosion, then respawn as normal (or not respawn, if no stocks remain). Instant KOs were introduced as stage hazards in Super Smash Bros. Brawl, and a greater variety of attacks and conditions causing instant KOs were added in Super Smash Bros. 4 and Super Smash Bros. Ultimate, the latter game introducing instant variations of Screen KOs. Several instant KOs require the opponent to be at a certain damage threshold in order to be instantly KO'd, otherwise they will be launched as usual.
In Super Smash Bros. Brawl
In Super Smash Bros. 4
In Super Smash Bros. Ultimate
Playable characters' standard moves