Coin

Coins (sometimes known as Gold Coins or Yellow Coins, and also called Mushroom Coins in the Beanbean Kingdom and Koopabits in the Nintendo Comics System stories) are the main currency of the Mushroom Kingdom. They first appeared in Mario Bros., where they moved along the floor and were worth one hundred points if Mario or Luigi caught them. They later appeared in Super Mario Bros., where they were demoted to ten points per coin. If Mario jumped up and hit a ? Block, sometimes Coins would pop out. When one hundred Coins were collected, the player was rewarded with an extra life.

Mario Bros.
Coins first appeared in Mario Bros. where they were a rare item. If obtained, they give Mario or Luigi 100 points. They moved along the floor and can be an issue to catch if the player also regards the enemies that can distract Mario and Luigi.

Super Mario Bros.
In Super Mario Bros., coins were the most common items to get obtained in this game. They can be found in every level, spawning from blocks, floating in the air, or as a result from defeating enemies from a fireball. Coins were worth 10 points to collect them and collecting 100 coins will restart the coin amount and will give Mario an extra life.

Super Mario Bros.: The Lost Levels
Coins can also be commonly found in Super Mario Bros.: The Lost Levels. They serve the exact same function and appearance as Super Mario Bros., which they will grant Mario a life by collecting all of them.

Super Mario Bros. 2
In Super Mario Bros. 2, Coins could only be retrieved by using a Magic Potion to create a door near unpicked Vegetables. When this door appeared, the Mario, Luigi, Toadstool, or Toad could use it to travel to Subspace and pick out the aforementioned Vegetables, who would then be extra point-rewarding Coins.

Super Mario Advance introduced a new type of giant, red coin called the Ace Coins. Regular coins could also be found, although they were harder to find (and, as was in the original Super Mario Bros. 2, could only be found in Subspace).

Super Mario Bros. 3
Coins reappear as, once again, common items to be obtained in Super Mario Bros. 3. They still grant Mario a life when all of them are collected and will still be found in blocks, enemies, and floating in the air.

Super Mario World
Coins acted in nearly the same manner as in the previous games. However, the coins will slide on the ground if Mario defeats enemies with a fireball. They will still grant Mario a life if 100 are collected.

In most levels, Dragon Coins will appear. Dragon Coins are coins with an oval shape, with a profile of Yoshi in it. If Mario collects all 4 of them in a level, he will get a life and it will act towards completion if Mario collects all. If Mario collects all Dragon Coins in every level there are Dragon Coins, there will be a scene and after that, the Dragon Coins will be replaced by Peach Coins, which serves the exact same function.

Super Mario Land 2: Six Golden Coins
Coins had a very important role in Super Mario Land 2: Six Golden Coins. Six Golden Coins were actually the key to Mario's Castle, and Wario had scattered these Coins across Mario Land. Each Golden Coin was guarded by a different creature; Ricky, Radonkel, Sabasa, Tatanga, the Three Little Pigheads, and an Octopus were all guardians of the Coins. Regular Coins could also be used to buy extra lives and power-ups through a gambling minigame whose stats could be changed depending on how many Coins were spent.

Mario is Missing!
In Mario is Missing!, Luigi had to return coins to the Trevi Fountain in Rome which were stolen by Koopa Troopas. Legend says that whoever throws coins into the fountain will return to Rome one day. When Luigi returned the coins, he was rewarded $1500.

Super Mario 64
Coins are common once again in Super Mario 64. Unlike its preceding games, coins can be found by simply defeat the enemy. Collecting 100 coins in a level will make Mario earn a star. If Mario happens to collect 50 coins in a level and he completes the level, he will earn a life. Red Coins reappear and they are scattered throughout the level. If the player manages to collect all red coins, then a star will appear. Red coins are worth 2 regular coins.

Blue Coins debuted in this game. They are found usually by ground-pounding on Blue Coin switches or defeating certain enemies such as Boo or Mr. Eye. Blue coins are worth five yellow coins when collected.

In Super Mario 64 DS, all coins returned. The only difference is that some extra levels require the player to collect red coins as well to make stars appear.

Luigi's Mansion
Coins were the most common treasure in Luigi's Mansion. They were worth 5000 G, and could be found all over the mansion. Whenever Luigi took damage, he would lose a few Coins, which would disappear if they were not reclaimed quickly enough.

Super Mario Sunshine
Coins also serve the same function in Super Mario Sunshine. They still grant Mario a life if a certain number are collected. Blue Coins also return and they serve a big role in order for 100% game completion.

New Super Mario Bros.
In New Super Mario Bros. coins are found by defeating enemies or finding them floating in the sky, just like Super Mario Bros. Star Coins are also found in this game. 3 Star Coins are found in every level, which can be hard to obtain these coins. What the player does if he/she has Star Coins is to spend them on fences and background for the bottom screen. If the player collects all Star Coins and spends them on everything, the file will receive 3 stars, indicating 100% completion. Red Coin rings are present in this game. If the player touches the red coin ring, 5 red coins will appear. If the player receives all 5 red coins, he/she will receive a power-up, which will depend on the player's certain condition.

Super Mario Galaxy
Coins are much rarer in this game than the other preceding 3D games; Star Bits probably replaced coins as being a common item that grants Mario a life for every 100 collected. However, coins still do appear and unlike Star Bits, they can heal Mario when collected. Mario can acquire these coins by shooting a yellow spot on the ground or stomping on an enemy instead of spinning it. Collecting 50 of these coins will earn Mario a life.

"?" coins are also found in this game. They are bigger and cause miscellaneous effects to take in, such as music notes appearing to collect or producing a trail of Star Bits.

Purple Coins are also introduced in this game. In some of the missions in the game, Mario or Luigi needs to collect 100 Purple Coins in order to obtain a Power Star. They are scattered all over the galaxy and sometimes have a time limit to collect them all.

New Super Mario Bros. Wii
In New Super Mario Bros. Wii coins, red coins, and Star Coins return. All serve the same function, including the red coin ring reappearing. Star Coins are used for a different purpose, however. Collecting all Star Coins in each world will give the player access to the levels in World 9, Star World. Collecting all Star Coins in this game will earn the player a star in the save file.

Super Mario World 2: Yoshi's Island
Coins were common throughout each level in Super Mario World 2: Yoshi's Island. They acted in the same manner as the previous games, but this game introduces Red Coins. Red Coins are disguised as regular coins in each level and the player collects all red coins, the player will make the game closer to 100% completion.

Yoshi's Island DS
The functions of the coins in Super Mario World 2: Yoshi's Island and Yoshi's Island DS are relatively the same. New coins are introduced which are bigger and portray the baby character's head on them. Collecting them will make the player earn a reward.

Mario & Luigi: Superstar Saga'
Mario & Luigi: Superstar Saga introduces regular coins and Beanbean Coins. Prince Peasley made a bet of 99,999,999,999,999 Mushroom Kingdom Coins with Mario and Luigi, about who should find the pieces of the Beanstar first. Mario and Luigi win, and Prince Peasley rewards them with the promised coins. However, since they were Mushroom Kingdom Coins, the exchange rate translated into only 99 Beanbean coins. This game also introduces Smash Coins.

Mario & Luigi: Partners In Time'
Mario & Luigi: Partners In Time also returns regular coins. Most of these coins can be obtained through blocks or by defeating enemies. In some places, there are larger yellow coins and blue coins that can only be obtained by spinning Baby Mario and Baby Luigi through the air and into the tornado, making them soar farther and descending to collect the coins. Like Mario & Luigi: Superstar Saga, coins are also used for currency in this game.

Mario & Luigi: Bowser's Inside Story
Mario & Luigi: Bowser's Inside Story also had a similar way of collecting coins very much like the previous games. Most coins are found in blocks and by defeating enemies. Coins are needed to by more accessories and items to help the player out.

Mario Kart Series
In Super Mario Kart, Coins were found at each course. Collecting them would make karts faster. When jostling another driver or getting hit by an item such as a Red or Green Shell, the player would lose Coins. Jostling a driver without having any Coins would result in sliding. There was even an item providing the player with two extra Coins. Mario Kart Super Circuit had the same functions as Super Mario Kart, but without the extra-coin item. There is an option in this game to remove the coins, but it is only applicable to Quick Run mode.

Mario Party Series
Coins were needed to win the game in the Mario Party series. Without coins, the player cannot purchase stars, the main item in order to win, or items that can help the player. Coins can be acquired by landing on a Blue Space, certain Happening Spaces, and Donkey Kong Spaces. Also, 10 coins are acquired every time a player wins a minigame. Coin minigames exist, which can make the player receive a certain number of coins depending on the coins found in this game.

Mario Baseball Series
In both Mario Superstar Baseball and Mario Super Sluggers, coins played a role in both of the challenge modes and both of the Toy Fields. Coins are needed in both games to buy items to either unlock events or help the player when he/she is playing with someone else. In Toy Field, coins are needed to win the game, and coins could be obtained by hitting an RBI or the Hit spaces in the field. Though similar, both Toy Fields have different ways of getting coins, such as shooting an item at an opposing player in Mario Super Sluggers or get a right item in a slot in 'Mario Superstar Baseball.

Paper Mario Series
In the Paper Mario series, Coins are fairly common. Coins will appear whenever an enemy is defeated. However, when Mario runs away from a battle, he will lose coins. However, not only do Coins come from usual ? Blocks, but they come from trees and bushes Mario could find in various places. To get a single coin from a tree, Mario has to use his Hammer to make the tree shake so that the single coin would fall down. To find the single coin in a bush, Mario simply tried to search a bush when he went near one.

Super Paper Mario
Super Paper Mario explains that Coins came from the Sammer Guy warrior Footsteps of Coins, who is the one who purposely drops coins around the universe but this explanation is merely part of Footsteps of Coin's opening speech, so its accuracy can be considered poor. In Super Paper Mario, each enemy releases coins when defeated. The stronger the enemy, the more coins are released. Instead of Mario having to pick up coins, they hit the ground and are instantly collected. The coins serve as currency to buy items (or, after the end of the game, the rare Pixl Tiptron). A total of 999 coins can be held by Mario in this game, any more will disappear. In this game, coins can also be gained using the Happy Flower to produce coins, or selling items for coins. Some items also increase the number of coins gained after defeating an enemy.

Yellow Coins
Yellow Coins are the main types of coins found in the Mario series. They are found everywhere ranging from floating in the air, from acquiring through blocks, to defeating enemies. They are worth 1 coin point and 10 points if the player collects them in platforming games. Collecting either 50 or 100 in certain games will make the player earn a single life.

Red Coins
Red Coins are uncommon, but not rare in the Mario series. They first appeared as coins disguised as yellow coins in Super Mario World 2: Yoshi's Island, but later on, they are found in certain parts of a level or scattered throughout the level. They are worth more than Yellow Coins, each is 2 coin points.

Blue Coins
Blue Coins are either part of completion of a game or another way of getting more coins. Blue Coins are found in hidden parts in Super Mario Sunshine and are required in order to complete the game 100%. In Super Mario 64, they are found by defeating certain enemies or ground-pounding a blue coin switch. They are worth 5 coin points each.

Purple Coins
Purple coins are only found in Super Mario Galaxy when a Purple Comet is orbiting a galaxy. Purple coins can appear through out a level or they can appear in a spot within a certain amount of time. If the player can collect all Purple Coins, he/she will receive a star.

In a screenshot, Purple Coins are present in Super Mario Galaxy 2. Functions of these purple coins are not yet known.

Dragon Coins
Found only in Super Mario World and remakes, these will grant Mario a life when 5 collected in each level. Some levels have less Dragon Coins than other levels, but most of the time, there are 5 Dragon Coins. They are bigger than regular coins and they have a portrait of Yoshi on them.

Trivia

 * There has been much controversy over the correct capitalization of the word "Coin"; most games use the proper "Coin" in reference to the Coin as an item but simply use "coin" when using it to label prices. As such, most games interchangeably use both "Coin" and "coin" depending on usage.
 * In Super Mario Land 2: Six Golden Coins, a glitch existed that could turn Mario into a variety of sprites; these sprites included all frames of a Coin's animation, effectively allowing the player to control a Coin.
 * A Sammer Guy named Footsteps of Coins claims that it is he who hides the coins around each game.
 * In Luigi's Mansion, the crown of King Boo was equal in value to one Gold Coin (5000 G).