Swim

Swimming is an action that can be used by several characters. Swimming is typically done in water, sometimes with an associated air meter, with other substances able to be swam through infrequently.

Super Mario series
Swimming is a staple mechanic of the series, first being possible in Super Mario Bros. and going on to be in every mainline title except Super Mario Bros. 2, Super Mario Land, and Super Mario Run. In the 2D games, swimming mechanics have remained largely unchanged; Mario naturally sinks in water and swims upwards by pressing the jump button, preserving his forwards momentum. There is no air meter, allowing Mario to stay underwater indefinitely.

In the 3D games from Super Mario 64 through Super Mario Galaxy 2, the swimming mechanics are different. Mario is aimed in any direction using the Control Stick, with the jump button propelling Mario forward in that direction. He does not naturally sink in the water when not actively swimming. Additionally, an air meter is added, which causes Mario to take damage and eventually drown if he is underwater for too long without collecting an Air Bubble. In Super Mario Galaxy and its sequel, Mario is able to use the Star Spin to propel through the water faster than normal swimming. When playing as Luigi, he loses air with every Star Spin.

Starting in Super Mario 3D Land, the swimming mechanics are changed to imitate the mechanics of the 2D games. Mario gains the ability to Ground Pound underwater, allowing him to quickly descend in the water. Super Mario Odyssey maintains the rising-and-sinking swimming, but includes the air meter. Mario can also use the new Quick Swim move with +, which propels Mario forward similar to the Star Spin in Super Mario Galaxy.

Several items and powerups allow Mario to swim faster or with more control. The Frog Suit in Super Mario Bros. 3 and Super Mario Maker 2, and the Penguin Suit in New Super Mario Bros. Wii and New Super Mario Bros. U allows Mario to automatically swim much faster by holding down a direction. In Super Mario 64, Super Mario Galaxy, and Super Mario Galaxy 2, grabbing a shell allows Mario to automatically swim forward in the water very quickly. In Super Mario Sunshine, using the Hover Nozzle underwater will propel Mario forward. In Super Mario Odyssey, capturing a Cheep Cheep allows Mario to swim through the water quicker and without regard for the air meter.

In Super Mario Maker 2, in the nighttime version of the castle theme, Mario and the other playable characters are able to swim in mid-air with the same mechanics as water.

Donkey Kong Country series
Swimming has been a part of Donkey Kong Country since the first game in the series. In the SNES games, the Kongs can swim through the water simply by moving the control stick. They are helpless underwater without the help of Enguarde, who can dash forward and stab enemies with his sharp bill.

Donkey Kong and Diddy Kong are unable to swim in Donkey Kong Country Returns; the Kongs simply die when touching water. Swimming is brought back in Donkey Kong Country: Tropical Freeze, where the Kongs are able to swim in 360 degrees, as well as use a new spinning attack by pressing the roll button. Dixie Kong is able to propel faster underwater with her hair.

Super Smash Bros. series
In Super Smash Bros. Brawl, Super Smash Bros. for Wii U, and Super Smash Bros. Ultimate, fighters are able to swim across water. However, they will drown if they remain in the water for too long and lose a stock, the time required based on the character's percentage. In Super Smash Bros. Ultimate, Charizard, Sonic, Inkling, and Incineroar take a small amount of damage while swimming. There are stages in Super Smash Bros. Melee and Super Smash Bros. for Nintendo 3DS that include water, however, fighters simply fall through it. These stages' water is made swimmable in their Super Smash Bros. Ultimate incarnations.