NonCredibleDefense

I misspelled it; it should be galdrastafir. It literally translates as 'magic staves', but it's understood to mean symbols that are a part of a magical spell. ...Or 'magickal' if you want to draw a distinction between parlor tricks and 'real magick'. The books that contained them were sometimes called galdrabók, although that's also the name of a specific grimoire. It's complicated because, while galdrastafir are currently believed to be explicitly magical, in some cases they appear in books alongside herbology, which would seem to indicate that either they weren't contemporarily perceived as 'magic' per se, or that herbology was.

Anyway. It's a form of folk magic. The general idea is that you draw or scribe a specific symbol on a certain kind of object, perhaps with particular tool, and use the object in a specific way, and it will produce some kind of effect that would not otherwise happen. The most well known ones are ægishjálmur (the helm of terror; said to protect you in battle, make other people fear you), and vegvísir (a compass to help you find your way home in bad weather; supposedly used by sailors). But there are a lot of others as well. Draumstafir was a symbol scribed in silver on wood (linden, maybe?, I don't remember anymore) that was supposed to let you dream at night of what you most desired.

Supposedly--and there's not a ton of really solid, scholarly writing about this--the Catholics were pretty forgiving of the people practicing folk magic, as long as the people were still paying their tithes. Supposedly a Catholic bishop (?) in charge of the area was also a practitioner of black magic, and had a grimoire called the rauðskinna full of exceptionally powerful spells. When Denmark became Lutheran, they also supplanted the Catholic heirarchy in Iceland with Lutherans. The Lutherans were quite a bit less accepting of folk magic; they burned ever grimoire that they came across. So there are only a handful of examples that still survive, and they all date to late 1700s to late 1800s. Keep in mind that Iceland was very backwards relative to Europe until fairly recently, so it's entirely conceivable that there are people currently alive that had grandparents that were galdr practitioners.

/autistic monologue