The Four Rarities

Let's first review the default usage for the four rarities in the game and how these already start to tell a story about your universe.

• Common elements are prevalent enough, at least among adventurers, that a player is assumed to be able to access them provided they meet the prerequisites (if any).
• Uncommon elements are difficult to access or regionally specific, but a PC can usually find them eventually with enough effort, potentially by choosing a specific character option or spending substantial downtime tracking them down.
• Rare elements are lost technology, ancient magic, cutting edge biotech, and other options that PCs can access only if you specifically make them available.
• Unique elements are one of a kind, like a specific magical artifact, one-of-a-kind prototype, or a named creature. You have full control over whether PCs can access them. Named NPCs are unique creatures, though that doesn't mean their base creature type is unique. For instance, a shirren named Zazi is unique, but that doesn't mean it would be any harder for a PC encountering her to tell she's a shirren—just to discern specific information about her.