Damage is the basic measure of how vulnerable a character is to the knockback of attacks. At low damages, the character cannot be knocked back very far, and can only be thrown off-stage by the game's most powerful attacks. However, at high damages, attacks deliver considerably more knockback, increasing the risks of severely damaged charcters to be KO'd.
Damage starts at 0% and can rise all the way up to 999%. Though damage is displayed as a percent, getting to 100% does not mean a character is doomed - the number itself is somewhat arbitrary. Damage is measured as an integer in Super Smash Bros. and a decimal number in Melee and Brawl; a damage with a decimal part is rounded down when displayed.
Each attack deals a set amount of damage, which is then modified by things such as Stale-Move Negation before the target is launched. An attack that does no damage will not cause targets to flinch and not produce a regular hit sound, although it will still cause knockback. The damage an attack deals is a significant factor in how much knockback it causes.
The following things are affected by damage:
Should a tournament match time out and the players have equal stock remaining, whoever has less damage is the winner, and a tiebreak procedure is followed should damage also be even.
 Damage meter
The damage meter displays the damage percentage a character has accumulated from attacks, as well as the character's universal symbol and number of stock remaining; unique to Brawl is a display of the character used, and the character's name. In all games, the number of stock remaining is visually represented by the number of icons (the character's mugshot in the original game and Melee, nondescript circles in Brawl); a stock of higher than five is represented by one stock, with a multiplier value next to it; having fifteen stock, for instance, would show "x 15".
Damage meters are displayed at the bottom of the screen during gameplay. While normally opaque, damage meters in Brawl become translucent if a character is "standing" behind it. The damage percentage itself changes colour when more damage is acculumulated; at low percentages, the value is white, but the value gradually turns a darker black (original and Melee) or red (Brawl only) as the value increases.
Additionally, in all three games, the colour of the series symbol behind the damage percentages changes depending on the player's number. Player 1 would receive a red symbol, Player 2 has blue, Player 3 has yellow, and Player 4 has green, while all CPUs have a grey colour; in Brawl, the "underline" underneath the meter would also have a corresponding colour.
 See Also