Trio Move

Trio Moves are field moves found in Mario & Luigi: Paper Jam. Paper Mario comes up with each move when the brothers find themselves stuck in a new situation. There are a total of four moves, which can be selected through either touching the appropriate icon on the touch screen, or cycling between the two using the L and R buttons. All Trio Moves can be activated by pressing A-B-Y in sequence.

Trio Jump
The Trio Jump is not necessarily a trio move, and is not learned the same way the others are. It is activated instead by pressing X, no matter what Mario's current action icon is. By using the Trio Jump, all three brothers will jump and hover for a moment, allowing the player to control their movement more finely than jumping individually. The Trio Jump does not achieve the same height as a regular jump, and thus cannot hit ? Blocks or climb certain cliffs. Trio Jumping is necessary to begin using the Dash Socks.

Trio Hammer
The Trio Hammer is the first trio move learned, in the Doop Doop Dunes. Mario, Luigi and Paper Mario combine their hammer swings, unleashing a large shockwave that can stun enemies and break large bricks. It can also flip over paper constructs in the field, revealing flowers and/or coins. It is the only Trio move that does something when left unfinished: Mario swings his hammer as normal, and Luigi can add his hammer swing to take out Pokey cacti.

Trio Grab
The Trio Grab is the second trio move learned, in the Twinsy Tropics. Mario and Luigi, connected by Paper Mario folded into a cylinder, can stretch out and grab far away objects such as coins, bridges, and poles to cross small abysses.

Trio Drill
The Trio Drill is the third trio move learned, on Mount Brrr. Mario and Luigi, aided by a conical Paper Mario, drill into the ground. They can move around, and even dash. This can dig up buried beans, coins, and items hidden in paper terrain. By dashing into a wall, the trio can do this on walls, and dashing out of the sides of a wall allows the three to soar forward, potentially into another wall.

Trio Aeroplane
The Trio Aeroplane is the final trio move learned, in Bowser's Castle Mario and Luigi, aided by Paper Mario folded into a paper airplane, can glide over large gaps, with the option of soaring higher into the air three times (plummeting faster after every use of the move). The Airplane makes two cameos in battle: certain bosses can use attacks in which Paper Mario uses his plane form to help Mario and Luigi dodge, and one of Bowser Jr.'s attacks is a paper plane contest using Paper Mario and Paper Bowser Jr. as the planes.

Trivia

 * The Spin Jump makes no appearance in this game. However, it appears to have been (situationally) replaced by Trio Grab.