This move is the same regardless of which Pokémon uses it: Pokémon Trainer brings out all three of his Pokémon to attack together. Squirtle uses Hydro Pump, a multi-directional spray of water in Brawl and a whirlpool in Ultimate. Ivysaur uses Solar Beam, a narrow beam of concentrated light, to create a massive projectile which can hold targets in place within the blast. Charizard uses Fire Blast, firing six large star-shaped flames, which also act as the finishing hit of the move. After several seconds, Pokémon Trainer recalls the two Pokémon that were brought out for the move, and the Final Smash ends.
During this move, a text box (like the ones in Pokémon games) appears on the bottom of the screen, which states, "Take that! Triple Finish!", while Pokémon Trainer shouts the same thing out loud. If the move successfully damages an opponent, the text changes after a moment to "It's super effective!"; otherwise, the first message will remain for the duration of the attack. The text box hides damage meters and appears in Snapshots. The camera also zooms in on the trio at the start of this move, slowly zooming out as the attack goes on.
The move does more damage to opponents that are closer to the Pokémon, where all three moves will hit at once. When an opponent is as close as possible, they can take up to 57% damage. However, if the opponent is too close, they will be sent straight up and out of the attack by a concentrated ball of energy in front of the Pokémon. The move can be used in mid-air, in which case the team will hover in place for its duration.
In Super Smash Bros. Ultimate, the female Pokémon Trainer now says "Go! Triple Finish!", while the male Pokémon Trainer now properly says "Take that! Triple Finish!"; the second message, "It's super effective!", shows regardless of whether the attack hits any opponents. Also, Charizard fires five Fire Blasts instead of six.
All three of the attacks used in this Final Smash - Hydro Pump, Solar Beam (formatted as "SolarBeam" prior to Generation VI) and Fire Blast - have featured in every main installment in the Pokémon franchise. Prior to Generation III, these moves were known for being the strongest moves of their types (Water, Grass, and Fire respectively). They are each Special moves with a very high base power of 110 (120 for Solar Beam and prior to Generation VI), but each one has a drawback to offset this: Hydro Pump has an accuracy of 80%, Solar Beam must be charged for one turn before it can be used along with its power being cut in half if there is a weather condition (except in the harsh sunlight weather condition), and Fire Blast has an accuracy of 85%.
The concept of three Pokémon being active at once was not possible in the Pokémon series at the time of Brawl's release. However, while introduced after Brawl, Triple Battles were introduced in the Pokémon series in Generation V, where each Trainer sends out up three Pokémon at once. By using Hydro Pump, Solar Beam (the attacking portion) and Fire Blast during the same turn during a Triple Battle, it is possible to emulate Triple Finish in a Generation V or VI Pokémon game. Prior to Brawl, however, an episode of the Pokémon anime featured the first non-official Triple Battle in the series.
The text box that appears in the Smash move resembles the text boxes that traditionally appear during battles in the Pokémon series, describing what actions are taken and the effects of said actions. The style of the text box resembles the latest installment of the series in each game the move is featured in—Diamond / Pearl in Brawl and Sun / Moon in Ultimate. However, neither of those two sets of games features Triple Battles as a mechanic.
The phrase "It's super effective!" has been used ever since the first generation in the series, whenever the type of a move used by a Pokémon is strong against the typing of the opposing Pokémon (for example, a Fire-type move against a Grass-type Pokémon). In these instances, the attack deals double or quadruple the normal amount of damage, and is additionally accompanied by a different damage sound effect.
The Final Smash of the Pokémon Trainer. Squirtle, Ivysaur, and Charizard join forces to simultaneously use Hydro Pump, SolarBeam, and Fire Blast. This is the only time all three of them appear on the screen together, so this move boasts the strength of three in one. A window will appear on the screen, but don't worry about it.