Characters and Animals
These characters only die once. If looted and left alive after a fight, they can regain their health and items when the player reloads their location. Many of these characters are tied to a World State.
Unique animals will not survive looting since animals die when you rip them apart. If left alive and healed, unique animals can be returned to and fought again.
Unique Items
These items only spawn in a couple specific places. They may be death items which are only found on unique animals or lore items which are easy to miss.
To decrease clutter, Lore Books will not be included in this list.