Coin
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.
Different types of coins began to be developed in Super Mario World. The Dino Coin was a special coin that only be found in certain places. There were only five in each level.
Super Mario World 2: Yoshi's Island also introduce Red Coins, which were disguised as regular Coins until Yoshi touched them. Super Mario 64 introduce Blue Coin, and Yellow Coins, 2 more different types of coins.
Super Smash Bros. Melee had a special type of match called Coin Battle, where Coins would double as a players health, and whenever a player was hit, Coins would come out. The character ending with the most coins wins. Coins also got 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.