There are so many currencies in the world of Hades, it's probably overwhelming for a beginner. Some of them come in a form of items, but they are pretty much work as currencies in the game. Below is a list of all currencies sorted by their rarity:
- Gold: is the most common currency in the game. It is used to buy items during the game plays. Sometimes, you can use it to buy other currencies as well from the Well of Charon and Charon (Shop).
- Darkness: is the second most common currency. Darkness is used to upgrade Mirror of Night.
- Gemstone: is a bit rarer than Darkness. You need Gemstones to purchase work orders from House Contractor.
- Chthonic Key: similar to Darkness, Chthonic Key is used to unlock perks from Mirror of Night. Increasing bonds and eventually unlock more storyline and Companions.
- Nectar: is useless on its own. It is mainly use for gifting other characters in the game for
- Diamond: is also mainly use for purchasing work orders from the House Contractor.
- Ambrosia: just like Nectar, when you gift Nectar to characters to a certain point, you'll have to gift Ambrosias instead.
- Titan Blood: This is probably the most important currency. Titan Blood is used to unlock/upgrade Weapon Aspects.
I know that's a lot of things but you'll get used to it very soon. I would recommend you try to finish to the game once to unlock the Pact of Punishment so that you can farm Diamond, Ambrosia, and Titan Blood faster. See Grinding section.