Magic is probably the one ingredient that is integral to fantasy. And of course, there are as many magical systems as there are authors of fantasy. That is a good thing.
Now, magic is not prominent in my Lar Elien world. I wanted to write adventures, basically, with some magic thrown in to make it easier for my hero Andert to survive things that normal knights would succumb to. So I invented his sword, Sturmlied. (I’m thinking about keeping the German name in translation, so I’d be glad about feedback on this.) The sword’s power is basically healing, but it can do more than its creators intended, because a dark mage played around with it for several years. Sturmlied can thus surprise even Goswin (which gives me some leeway to play with the sword’s abilities, ahem).
From what I saw of the world of Lar Elien, mages are far and few between. I’m not sure yet how the knowledge is transferred, but there are more „bad“ mages than „good“ ones. Maybe a certain egoistical mindset provides more motivation for the hard work needed to become a mage, and maybe a certain cruelty is needed in order to test most magic. I suppose there are some scrolls around that detail spells, but most of it is work by the mage him- or herself. I would also expect apprentices, but I haven’t seen any yet. (Now … here’s an idea for a short story. My plot for the Disillusioned Mage would fit into this world.)
I also haven’t encountered many magical objects – most of them were swords, or daggers, but there are some protective amulets, as well. Another product of magic are altered animals, which are called monsters by the people. The world of Lar Elien has quite a few of those, so maybe tinkering with genetics is easier for a mage than enchanting objects. Magic can also be used to enthrall people – something similar to yet stronger than hypnosis – by taking control of their minds.
I have no „system“ of magic in Lar Elien. Somehow, I never got around to it, and decided that mages are too indiviual to press into systems. Lazy? Probably. So far, it’s working, I think. Andert does run into some mages and several monsters, but he also deals with plain criminals and evil plots. Sometimes, even nature tests his mettle.
Magic in my world is sporadic, individual, non-organized and waning. Even so, magic always has a price. It takes effort to work. It takes a lot of time to study it, time that cannot be spent in earning money or building a living. Mages are rarely well integrated into society, most of them live alone or in a family group removed from towns and villages. Some go mad. Many lose their integrity once they realize how much more they can do than the ordinary person.
So, while magic is not central to most people, it still is part of the fabric of Lar Elien. And you never know when or where my heros will encounter magic. In fact, that’s often a surprise for me, as well.