Blast line

A blast line, also known as a death boundary, is a boundary on a stage in the  series and Fraymakers that a character cannot cross without getting KO'd. There are four blast lines, usually referred to as "upper"/"higher", "bottom"/"lower", "left", and "right" (alternatively, "north"/"south"/"east"/"west"). The bottom blast line can also be referred as the "pit" and the upper blast line can also be referred as the "ceiling."

On most stages, all four blast lines are accessible and located far away from the stage's platforms. Some stages, such as Peach's Castle in Super Smash Flash or Lake of Rage in Super Smash Flash 2, have platforms extending all the way to the left or right blast lines, which are referred to as walk-offs. Other stages, such as Sand Ocean in SSF2, have full floors or walls that prevent access to certain blast lines, though they can still be reached through glitches. Notably, PAC-MAZE in SSF2 features blast lines that, with hazards turned on, cause the player to warp to the opposite blast line unless knocked into it by an opponent.

In the original SSF, all four blast lines cannot be crossed in any way without resulting in a KO. In SSF2 and Fraymakers, however, the upper blast line is different from the others in that characters can freely pass it in most situations. Characters are only KO'd from this blast line if they are knocked into it or are standing on platforms cross the blast line. Exclusively in SSF2, characters KO'd via the upper blast line are either star KO'd or screen KO'd.

In SSF2 and Fraymakers, the camera does not pan or zoom enough during gameplay to show the blast lines. When a character is outside the camera's view, they will appear in a bubble pointing to the edge of the stage, which appears as a circle in SSF2 and a square in Fraymakers. Exclusively in SSF2, characters slowly take damage while just outside the blast lines, which is referred to as hoop damage.

Trivia

 * In the original SSF, the upper blast lines of all stages except for Peach's Castle could be crossed merely by jumping high enough, making aerial camping with characters that have multiple jumps such as, , and a dangerous and self-destructive option.
 * Prior to v0.8a of the SSF2 demo, the characters KO'd via the upper blast line would neither be star KO'd or screen KO'd, and instead they would be KO'd normally.