Coin

Coins, (sometimes known as Gold Coins) are the main currency of the Mushroom Kingdom. They first appeared in Mario Bros., where they moved along the floor and were worth 100 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 100 Coins were collected, the player was rewarded with an extra life. Coins served the same function in Super Mario Bros.: The Lost Levels and Super Mario Bros. 3.

Other Coins
Super Mario Advance introduced a new type of giant coin called Ace Coins. Regular coins could also be found, although they were harder to find.

Another different type of Coin was developed in Super Mario World. The Dragon Coin was a special coin that only be found in certain places. There were only five in each level.

Coins had a very Important role in Super Mario Land 2: Six Golden Coins. Six Coins were actually the key to Mario' Castle, which Wario had scattered across the land. Each coin was guarded by a different creature; a Rat, a Giant Bird, Witchella, Tatanga, the Three Little Pigheads and an Octopus. Regular Coins could also be used to buy extra lives and power ups.

Super Mario World 2: Yoshi's Island also introduce Red Coins, which were disguised as regular Coins until Yoshi touched them. Super Mario 64 introduced Blue Coin, and Yellow Coins, 2 more different types of coins. Super Mario Sunshine followed the same formula as Super Mario 64.

Coins were the most common treasure in Luigi's Mansion. They were worth exactly 50g, and could be found all over the mansion. Whenever Luigi took damage, he would lose a few Coins.

RPG's and Tournaments
Super Smash Bros. Melee had a special type of match called Coin Battle. Whenever a player was hit, Coins would come out. The character ending with the most coins wins. A Coin also appears as a trophy in the game.

In the Paper Mario series, Coins are very common. Coins will appear whenever an enemy is defeated. However, when Mario runs away from a battle, he will lose coins.

Mario & Luigi: Superstar Saga introduces regular coins and Beanbean Coins. Prince Peasley made a bet of 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.