The universal currency of Hyrule is the Rupee, named after the real-world currency. Rupees resemble hexagonal crystals or gems and come in various colors that determine their value. Many other countries in the Zelda universe also use rupees as their currency, the only major exception being the Subrosians from "Oracle of Seasons," who only accept Ore Chunks as currency. In the original game, they were called "Rupies," the singular being "Rupy"; this was later changed. Subsequent games introduced more colors and sizes for Rupees, each denoting a specific value. Generally, green Rupees have the least value, while gold or silver Rupees have the most. In "Skyward Sword, Four Swords," and "Phantom Hourglass," cursed black Rupees called "Rupoor" exist. These steal a certain quantity of Rupees depending on their size.