Runes

Runes are ancient alphabets, technically referring to the ancient lettering used by the Germanic tribes, Anglo-Saxons, and Vikings, or to modern derivations and variations on those letters. While their exact origin is unknown, they seem to be related to early Etruscan or Italic writing, or some other alphabet derived from early western Greek letters, possibly modified to make it easier to carve on wood or stone.

It's just letters, folks. Nothing to get excited about.

Modern variations
One such modern derivation is found in J. R. R. Tolkien's fantasy novels The Hobbit and The Lord of the Rings. Another modern variation, the Armanen runes invented by the crank Guido von List, were used by the Nazi party during World War II as military rank and unit emblems (the SS logo is two Sig-runes). Rock and heavy metal bands (e.g., Slayer and Kiss) are fond of using the Sig-rune.

Incorporating a historical writing system into the New Age movement
While used as an alphabet for writing in much of pre-Christian Europe, Norse mythology includes reference to runes as supernatural mysteries discovered by Odin and of course runes are more mysterious than the Latin alphabet that we use. The fact that the word "rune" also meant "secret" in Old Norse helps, too. This ascribing of supernatural woo to the runes has led to a considerable interest in them in the modern New Age movement and Neopagans, who use them for fortune-telling and spell casting. Ralph Blum's The Book of Runes probably started much of this interest in runes among the New Age, but then again Blum chose his orderings randomly, created a previously unused blank rune (because there are 24 runes in the Elder Futhark and each copy of his book came with a 5x5 sheet of plastic "rune cookies"), and then assigned meanings based off his own beliefs with help from the I Ching, a fact even other runicists (if that's a word) point out and are horrified by.

The other main source of modern interest is the books of Stephen Flowers, alias Edred Thorsson, a Germanic "left-hand path" occultist who at least went back to the primary sources to get his meanings, but that doesn't make them any less full of woo. At least he has a legitimate PhD in Germanic Studies, though.

Linguistic importance
Proto-Norse is solely attested in runic writings and thus is tremendously valuable for Norse studies. But still, no magic, although some inscriptions were meant to be precisely that. A German scholar, whose name will not be mentioned out of clemency, undertook the task of analyzing Proto-Norse prosody on the basis of preserved inscriptions. Since the material was almost non-existent, the results were as could be expected. The conclusion was that Proto-Norse had some sort of prosody — all cultures have that — a variety of, but that could have been guessed without further ado.

As an example of a linguistically important inscription, we have this from one of the, one line for each word.

&#x16D6; &#x16B2;

&#x16BA; &#x16DA; &#x16D6; &#x16B9; &#x16AB; &#x16B7; &#x16AB; &#x16CB; &#x16CF; &#x16C1; &#x16C9;

&#x16BA; &#x16DF; &#x16DA; &#x16CF; &#x16C1; &#x16C3; &#x16AB; &#x16C9;

&#x16BA; &#x16DF; &#x16B1; &#x16C5; &#x16AB;

&#x16CF; &#x16AB; &#x16B9; &#x16C1; &#x16DE; &#x16DF;

In the Latin alphabet it reads:

ek hlewagastiz holtijaz horna tawidō. There are a couple of uncertain details, but it is still clear enough to wring quite a bit about Proto-Norse grammar out of it.