A fairth was an image or likeness produced by magic. It was created by mentally capturing the image one was currently intensely picturing and using magic to transfer it onto a surface, usually a slate tablet, with colored pigments imbued in it. Young Dragon Riders often did this to practice controlling their mind with great precision. It showed how well the rider was paying attention to all things, not just one. It was possible to create a false image with a fairth, though it is very difficult; usually only a very experienced Magic user could do this. Eragon never learned how to create a false fairth.
Oromis' fairths Edit
Oromis showed Eragon his fairth of the elvish city of Ilirea, created just before Gablatorix's capture and subsequent renaming of the city to Urû'baen. Once Eragon found out who his real father was, Oromis gave him another fairth, which was of his mother, Selena.
Eragon's fairths in Eldest Edit
Usually, Riders comprised an incomprehensible image the first time they attempted to make a fairth. Eragon, however, created an image that was focused on one thing first and the surroundings were unfocused and blurred. It was an image of sap on a broken bough. Soon after, Arya joined Eragon as he attempted to create a second fairth of the sap. Being able to focus on nothing other than Arya, he chose her as the subject of his fairth, expressing his romantic feelings for her in a tangible way. When she saw the fairth, she became enraged and broke it, causing the image upon it to vanish. After she stormed off into the woods, Oromis and Eragon discussed the implications of his actions, and Eragon began to understand better how his passion for Arya could not be realized at that time.
Eragon's fairth in InheritanceEdit
Towards the end of Inheritance Eragon made another fairth of Arya (During his first encounter with Fírnen). This time he managed to create an image that portrayed Arya not just as a subject of beauty but as a being with flaws and fears. He tossed the fairth to shatter it, but Arya stopped it in mid-air before it fell. Upon seeing the fairth, Arya was surprised and said that in time they might become more than just friends.