Similar to Rusted Bits, Debased Coins in Final Fantasy XV are pretty common treasures which Noctis can find throughout the world of Eos. However, unlike most other treasures, Debased Coins aren’t actually used to upgrade weapons through Cid. Instead, the treasure is used in crafting the Expericast spell from the Elemancy section.
The coins are relatively cheap and can be sold for a mere 150 Gil so it is advisable to hold on to them for crafting the spell as the Expericast can provide players with a massive EXP boost during combat, provided they have all the ingredients for a potent spell.
The spell requires some other currency as well including Rare Coins but the end result is worth it as the EXP gain can boost players really quickly if they just want to rush through the main story and don’t have time to level up properly for the main story missions.
Players will stumble upon Debased Coins from very early on in the game. In fact, the first Debased Coin is located at the Hammerhead Outpost. The coin is next to the parked oil tankers.
Two more coins can be found south of Hammerhead as players move towards Longwythe Rest Area. Players should be able to easily spot a group of six large silos. One coin is among the ruble near the silos while another is next to nearby car.
Debased Coins can also be easily found if players properly proceed through dungeons such as Keycatrich Trench or Glacial Grotto and search each area carefully.
Another Debased coin is in Altissia however players are unable to access the city before Chapter 8. Once in Altissia, they need to move towards the northern part of the city and look for a large metal statue near the Arena Galviano bound gondola.