Twilight of the Gods
Magic in Norse culture is complex – at once feared and powerful, coveted and misunderstood. There are a few general principles that apply to most magic, particular arcane magic. Odin is the source of arcane magic which is symbolized by the runes. Runes are usually cut into an object rather than written on paper, and their power can only be released when the are reddened by sacrificial blood.
For example, the way that Norse wizards prepare spells is to inscribe the runes for each spell into a strip of bark or a stick, and then to redden the runes with blood before-hand. When they are ready to cast the spell, they break or burn the runes, releasing their power. This is why the must prepare spells, and why they lose spells as they cast them.
Sorcerers call upon their innate magic, which is limited but more flexible. They still must prepare in order to cast spells, but their preparation is often mediation or other practices that help them center themselves and summon up their power.
In many ways, magic is associated with femininity – the power that women wield which men fear is that of magic, and the majority of oracles and seers are women. Most practicing priests are men, on the other hand, and they have authority over a given region with regard to the worship of the gods or a specific god.
Druidic magic is most widely practiced by the Sami people of Finland – it is thought to be a magical path that is older than Odin’s runes or the Vanir’s fertility, drawn from the spirits of the land themselves.
Magic is thought to gain its power from sacrifice. Perhaps this is why magic practitioners’ bodies do not develop as well as those of warriors. At the very least, even for spontaneous casters, it demands time sacrificed in study and materials sacrificed in experimentation when one is learning or creating new spells.