Mario Cap

Mario's Cap is an important part of Mario's clothing. The hat is red and has Mario's "M" symbol. This hat has appeared in every game featuring Mario (with the exception of the Dr. Mario games). Mario has worn the same hat since he was a baby.

Importance
Mario was given his hat in his first appearance in Donkey Kong because of the limited advances in video game graphics when the game was made. A red cap was added because programmers found it difficult to create the hair movement that would occur when the character jumped.

The hat has appeared with Mario ever since then, but was unimportant until Super Mario 64. This was the first game in which Mario could lose his hat. When the hat was lost (by having it stolen by an Ukiki or Klepto or blown off by a gust of wind), Mario would take more damage when attacked. The same happened in Mario's next platformer, Super Mario Sunshine, but with the added effect of gradually losing health. The only enemies that steal Mario's cap are Swipin' Stus.

In the remake of Super Mario 64, Super Mario 64 DS, a Toad revealed that the cap that Mario wears is special and if were to get blown off of Mario, he would have nothing but bad luck. As hinted in Super Mario 64 DS, Mario's hat may be a source of his strength. Mario's cap can also be found in most levels when playing as Yoshi. The cap will give the dinosaur the appearance and abilities of Mario, until he gets hurt and lose the cap. Luigi and Wario can also pick up Mario's cap, and gets the same effects as when Yoshi picked up one.

In Luigi's Mansion, Mario's Cap was one of the 5 items that Mario lost, and that Luigi had to bring to Madame Clairvoya.

Another sign of that cap's importance to Mario is at the end of Super Mario Galaxy 2, when the Baby Luma takes Mario's cap as a souvenir before returning to the Comet Observatory. Mario was shocked about losing his cap at that point. He is seen capless throughout the credits, but when he is playable again, he regains his hat somehow.

Versions
In Super Mario 64, Mario has four different types of hats: the Wing Cap (which enables Mario to fly), the Metal Cap (which enables Mario to walk underwater and to walk through fire), the Vanish Cap (which enables Mario to walk through certain walls) and his regular hat. While these powers were dispersed amongst Mario and his companions in Super Mario 64 DS, Mario's hat gained a new ability: when worn it could turn Luigi, Yoshi or Wario into Mario. If Mario loses his hat, he can't fly.

Additionally, due to certain glitches in Super Mario 64, Mario could end up with more than one hat, and could use the duplicate as an effective weapon. In Super Mario 64 DS, if someone wearing Mario's cap gets another hat, he instead gets an extra life. However, if the real Mario gets another one of his cap from a certain glitch in Snowman's Land, he'll pick up the cap and nothing will happen.

Trivia

 * In Luigi's Mansion, after Luigi scans the washing machine, it states that Luigi handwashes his hat while Mario just tosses his in the washer.
 * Also in Luigi's Mansion, Mario has two hats through the game, as he wears his throughout the entire game (even while Luigi or Madame Clairvoya are in possession of the collectible hat).
 * Mario's hat appears as an item in Nintendogs that the player's dog can wear.
 * Club Nintendo of North America released a replica of Mario's cap at the end of the 2009 Club Nintendo year as one of two rewards Platinum members could choose to receive.
 * In the game New Super Mario Bros. Wii, a little trick allows Mario to remove his hat when he gets 99 lives, though he doesn't die faster and still does the victory animation at the end of a level as if his hat were still there.
 * The players can buy and wear Mario's Cap in Animal Crossing: Wild World and Animal Crossing: City Folk.
 * Mario's cap can turn many colors, depending on which power-up he has. For example, if he has the Fire Flower power-up, his cap will turn white, and if he has an Ice Flower power-up, his hat will turn light blue, and so on.
 * Mario's Cap appears as one of the tokens in the 2006 version of Nintendo Monopoly.
 * Baby Mario's cap is on-purposely made larger, so it appears it was to big to wear when he was a baby.
 * On the Nintendo 3DS's StreetPass Mii Plaza, one of the unlockable caps for the player's Mii is Mario's cap.