Seesaw

Seesaws are a type of platform object that appear in many Mario games, and they usually tilt left or right depending on where the player and/or enemies walk on it.

Yoshi Franchise
Seesaws first appear in Super Mario World 2: Yoshi's Island, where they appear as bars of logs, similar to the Spinning Logs found later in the game, this bar is situated on a Post which ends in a wooden stake. The bar balances on this stake, and rocks back and forth when Yoshi isn't on it, if Yoshi stands on it, the seesaw will tip over until it topples. The seesaw will reappear soon after. If Yoshi directly touches the spike, it will damage him, dropping Baby Mario in the process.

Seesaw posts also sometimes have a different color like other posts, such as dark blue in cavern levels. Seesaws would reappear in various of the sequels, Yoshi's Island DS, Yoshi's New Island, and Yoshi's Woolly World.

Super Mario Advance 4: Super Mario Bros. 3
In Super Mario Advance 4: Super Mario Bros. 3, two Seesaws appear in the World-e level A Towering Tour. Players can make them tilt left or right by placing themselves on the corresponding side, and the Seesaws can do a full 360° rotation.

New Super Mario Bros. U / New Super Luigi U / New Super Mario Bros. U Deluxe
Seesaws appear in New Super Mario Bros. U as a type of platform found in the level Seesaw Bridge. They also appear in the New Super Luigi U level, Sumo Bro Bridge. Seesaws reappear in both levels in the Nintendo Switch port, New Super Mario Bros. U Deluxe. In these games, they rotate constantly and automatically, doing either full or partial circles, and are not affected by the weight of characters or enemies. Some of them also move up and down as they rotate.

A similar type of seesaw, the Seesaw Shroom, appears in all three games as a type of Mushroom Platform.

Super Mario Maker 2
Seesaws appear as a course element in Super Mario Maker 2. They are colored orange in the Super Mario World style, and red in all other styles. In the Super Mario Bros., Super Mario Bros. 3, and Super Mario World styles, they appear to be metallic, but in the New Super Mario Bros. U style, they are wooden. Like normal Lifts, their length can be changed, and they can be placed on tracks. They work similarly to their appearance in Super Mario Advance 4: Super Mario Bros. 3 (with the Super Mario Bros. 3-styled ones even resembling them), in that they tilt left or right depending on the player's or an enemy's position, but they can no longer do a full 360° rotation.

Seesaws can be abruptly tilted when a Thwomp falls on one side, throwing any playable characters and objects on the other side high into the air. This can also be achieved if a player Ground Pounds on the Seesaw (requiring a Dry Bones Shell to do so in the Super Mario World style and either a Dry Bones Shell or a big Goomba's Shoe in the Super Mario Bros. and Super Mario Bros. 3 styles). Furthermore, Bowser can perform this as well in the Super Mario Bros. 3 style using his Ground Pound attack.

Weight tier list
The following is a table listing the different weights of each course element.

In addition to these weight values:
 * Variations of a course element almost always weigh the same as their parent. This includes different forms of the player character.
 * Applying the Super Mushroom modifier to a course element doubles its weight. Wings and parachutes, on the other hand, contribute nothing to the weight.
 * While Giant Eggs have an initial weight value of 2×, the value becomes 1× once Red Yoshi hatches from the egg.
 * Pokeys and Snow Pokeys in particular have their weight multipliers increase by one for each segment added.

Super Mario Maker 2

 * North American website bio: "These are perfect for risky, tilt-centric courses."