Sting (Middle-earth)
Sting has the magical ability to detect orcs or goblins nearby, glowing blue in their presence, as it did when the Fellowship encountered orcs in the mines of Moria. Tolkien establishes this as a common property of First Age Elf blades, particularly those forged in Gondolin. Sting is also exceptionally sharp. Bilbo manages to thrust it without effort deep into a wooden beam at Rivendell. Frodo also wounds a troll in Moria, after Boromir notches his own sword with his attempt. Sam uses Sting to cut through the giant spider Shelob's strong webs with ease, and also wound the spider, driving it away from the paralyzed Frodo.
The Hobbit
Tolkien sent this revised version of the chapter "Riddles in the Dark" to Unwin as an example of the kinds of changes needed to bring the book into conformity with "The Lord of the Rings", but he heard nothing back for years. When he was sent galley proofs of a new edition, Tolkien was surprised to find the sample text had been incorporated. In "The Lord of the Rings", the original version of the riddle game is explained as a "lie" made up by Bilbo under the harmful influence of the Ring, whereas the revised version contains the "true" account. The revised text became the second edition, published in 1951 in both the UK and the US.