If you haven’t read the LAST TWO posts I put up on the magic system I’ve been working on for my NaNoWriMo novella I urge you to do so, as this continues exploring the topic by diving into the second foundational principle: Proximity.
Foundational Principle of Proximity
Unlike the Principle of Harmony, it is fairly easy to understand the implications of Proximity, which reads: Sigils require physical contact with their bearer to function. Similarly, the magic can affect closer targets more strongly. While this is fairly straightforward it comes with a few corollaries and side effects that are worth getting into.
But first we should explain exactly what it means. Using a sigil’s magic on a target that is 100 meters away will result in a weaker effect than using it on a target that is 50 meters away (for the same amount of silver burned). A sigil always acts most strongly on a target which the user is physically touching. It is possible to use something like a staff as an intermediary to touch something by proxy, although this is not as good as physical contact with the object itself and subject to limitations imposed by what the magic does (i.e. if the sigil acts upon metal than a metal rod will work quite well, while a wooden staff may provide no practical benefit).
The Principle of Proximity is why a sigil’s user must be in contact with the sigil if they wish to make use of it’s magic, and why the silver they burn in the process of using the magic (more about that in the post on Emolument) needs to be on their person. You might think this would also mean that a sigil would stop functioning for anyone other than the individual the Imperial Library created it for, however that isn’t quite the case. Those who share a blood relation to the original bearer can also use the sigil, although they will find it’s strength is notable weaker. The closer their relation, the stronger it will be.
Because of this a sigil can be passed on from the original user to one of their offspring (and their offspring, and so on), however over time the sigil’s power inevitably wanes due to the increased “distance” between the current user and the original bearer. Over time a sigil’s power will eventually become so weak that it is functionally inert, which is a fact the Imperial Library uses to help keep a leash on just how available sigil magic is within the empire.