Negative Zone (ネガティブゾーン) is Luigi's Final Smash. It has unique properties. Luigi dances, and a large, greenish-tint void surrounds him. Inside the void, the colors of the environment, the other characters inside the void, and Luigi himself become inverted. Opponents caught in the void fall victim to all sorts of afflictions given out randomly to opponents. Luigi dances and chants for the first few seconds of the Final Smash, but is unaffected by the Negative Zone (except a minor decrease in speed while still being faster than most other characters) when he's done. Even if Luigi is knocked out, the Final Smash does not immediately end. Using this move while over the edge may result in an SD as the zone sinks until Luigi's dance is finished and while he is dancing he cannot move. If opponents are caught in the Negative Zone, they become open targets as Luigi charges his foes and knocks them off the stage. It also appears that the Fire Jump Punch can be used to great effect, very often dealing a one-hit KO in the affected zone. When the Negative Zone disappears, the flowers and the dizziness opponents were given will remain and inflict slightly more damage after the Final Smash ends. Unlike any character's final smash, Luigi's Final Smash can pierce invincible opponents with any effect. If the player with Luigi was under Manaphy's Heart Swap and ends with switched opponent, the player with Luigi will be affected by Negative Zone and one opponent won't be affected when character enters the Negative Zone.
However, it's easy to escape by just rolling out, although the victim must still be careful to not get hit by Luigi. The move is very useful in team matches if one of Luigi's partners is a hard-hitter (e.g.: Donkey Kong, Ganondorf, Ike, Bowser).
 List of effects
(The invincibility from respawning does not stop the effects from taking place)
Characters inside the Zone are not guaranteed to have any of these effects at all times. Therefore, some lucky opponents can easily walk or jump out.
The move is unique to Brawl. However, the name may be a reference to Luigi always being in his brother's shadow, the fact that Luigi was originally just a palette swap of Mario's color scheme, the Negative Zone bonus areas in Super Mario Bros. 2, the infamous "Minus World" glitch in the original Super Mario Bros., the inverted overworld in Super Mario Bros. 2, or the fact that every color viewed through the bubble is changed into its false color.
 Trophy Description
Luigi's Final Smash. As exotic music plays, he performs a dance befitting a sorcerer's incantation. A barrier envelops him, negatively impacting all in his area. Random effects include getting launched, sleeping, moving in slow motion, tripping, fainting, and losing attack power. This technique is a reflection of the dark side he embraced in his brother's shadow.
Note that in the PAL version, the last line reads: In contrast to the oddness of the dance, this is a terribly powerful Final Smash.
The Negative Zone is one of the Final Smashes that can be affected by the Bridge of Eldin. Using it where the gaping hole is right when the bridge reappears does a small effect on the move. The Final Smash will activate, but Luigi fails to do the dance done in the first half of the duration of the move. This can provide an advantage to Luigi, as the player will be able to control Luigi the whole time and have more time to attack opponents and deal damage.