From Nookipedia, the Animal Crossing wiki
Medal NL Icon.png

Medals are the exclusive form of currency used on Tortimer Island in Animal Crossing: New Leaf. They are earned by competing in tours and can be used in the shop run by Grams. Medals are earned depending on how well the player does in a tour. Usually, the player has to exceed double the required amount or half the time given to earn the most medals in a tour. For instance, if 30 points are required to complete the tour, the player needs 60 points to earn the gold reward and earn the most medals.

If players earn plenty of medals, they can also win badges from Phineas. Here are the three ranks for the badges depending on the medals earned.

Bronze Medal.png Earn 300 medals
Silver Medal.png Earn 1,500 medals
Gold Medal.png Earn 5,000 medals