Following its predecessors, Brawl uses a battle system unlike that of typical fighting games. Players can choose from a large selection of characters, each attempting to knock their opponents off the screen as they fight on various stages. The characters in Brawl include most of the same ones as the predecessors, such as Mario and Pikachu. Instead of using traditional health bars that start at a maximum value and lose value, Brawl characters start the game with 0%; the value rises as they take damage, to a maximum of 999%.[15] As a character's percentage increases, the character flies further back when hit. When a character is knocked beyond a stage's boundary and disappears from the screen, the character loses either a life, a point, or coins, depending on the mode of play.[16] Brawl includes a function which allows players to create profiles with personalized button configurations for each control method along with their chosen username.[17]
The characters in Brawl fight using a variety of attacks, that give the player a wider selection than the predecessors. Players execute each move by pressing a button in conjunction with a tilt of the control stick or a press of the D-pad, depending on the mode of control. In addition to basic attacks, characters have access to more powerful moves, known as smash attacks. Each character has four unique moves, which often cause effects besides damage to an opponent. Brawl introduces character-specific super attacks, referred to as "Final Smashes". Significantly more powerful than regular attacks, these moves have a wide variety of effects that range from nearly unavoidable blasts to temporary transformations. Final Smash moves can be performed by destroying a Smash Ball: a colorful floating orb bearing the Smash Bros. logo.[18][19]
Characters can use items ranging from projectiles to melee weapons; each has a different effect on the characters around it. Although many items have returned from previous Super Smash Bros. games, new ones have been introduced as well. Some returning items have changed appearance and function.[20] Two varieties of items, Assist Trophies[21] and Poké Balls,[22] temporarily summon guest characters and Pokémon, respectively, that generally aid the summoner. They cannot be controlled by players and are usually invincible
