Defending a teleportation circle

Creating a public teleportation circle

The above description is not the only way to secure a public circle against magical tampering, but it makes the point that it is well within the capabilities of a city to maintain such a circle with minimal risk of having it dispelled by either random acts of magical vandalism or a dedicated antagonist. The guiding principle is that an unattended teleportation circle protected only by spells and other magic wards is not feasible, nor would any city want such a circle to exist. The circle must be guarded by people, not just spells.

The best modern analogy to a teleportation circle might be an international airport: people can arrive from anywhere in the world and the associated infrastructure is expensive and delicate, so the security practices must reflect that. (Let's ignore the questionable effectiveness of the security at real-life airports. Your fantasy security can be as effective or ineffective as you want it to be.)

Protecting your teleportation circle

Ok, but let's create a public teleportation circle anyway

The above description is not the only way to secure a public circle against magical tampering, but it makes the point that it is well within the capabilities of a city to maintain such a circle with minimal risk of having it dispelled by either random acts of magical vandalism or a dedicated antagonist. The guiding principle is that an unattended teleportation circle protected only by spells and other magic wards is not feasible, nor would any city want such a circle to exist. The circle must be guarded by people, not just spells.

In terms of worldbuilding, it's clear that a public teleportation circle like this requires quite a lot of upkeep, even more so than a private circle. At the very least, it would require full-time wages for both guards and at least 3 5th-level spellcasters (to cover the circle 24/7 with 8-hour shifts). Is it worth it for a city to pay this cost? Maybe it is, if providing teleportation access encourages increased long-distance trade in rare items (which the city can easily tax, since they control the teleportation circle).

The best modern analogy to a teleportation circle might be an international airport: people can arrive from anywhere in the world at any time bringing with them all manner of dangerous items, and the associated infrastructure is expensive and delicate, so the security practices must reflect that. (Let's ignore the questionable effectiveness of the security at real-life airports. Your fantasy security can be as effective or ineffective as you want it to be.)

The above description is not the only way to secure a public circle against magical tampering, but it makes the point that it is well within the capabilities of a city to maintain such a circle with minimal risk of having it dispelled by either random acts of magical vandalism or a dedicated antagonist. The guiding principle is that an unattended teleportation circle protected only by spells and other magic wards is not feasible, nor would any city want such a circle to exist. The circle must be guarded by people, not just spells. The best modern analogy might be an international airport: people can arrive from anywhere in the world and the associated infrastructure is expensive and delicate, so the security practices must reflect that. (Let's ignore the questionable effectiveness of the security at real-life airports. Your fantasy security can be as effective or ineffective as you want it to be.)

The above description is not the only way to secure a public circle against magical tampering, but it makes the point that it is well within the capabilities of a city to maintain such a circle with minimal risk of having it dispelled by either random acts of magical vandalism or a dedicated antagonist. The guiding principle is that an unattended teleportation circle protected only by spells and other magic wards is not feasible, nor would any city want such a circle to exist. The circle must be guarded by people, not just spells. 

The best modern analogy to a teleportation circle might be an international airport: people can arrive from anywhere in the world and the associated infrastructure is expensive and delicate, so the security practices must reflect that. (Let's ignore the questionable effectiveness of the security at real-life airports. Your fantasy security can be as effective or ineffective as you want it to be.)

Physically disrupting the runes in the sigil sequence (using, for example, a pickaxe) will prevent it from functioning, effectively destroying it. Obviously, this isn't as easy or as casting dispel magic from 120 feet away, but this method is available to anyone who can swing a pickaxe. Any circle must be protected against physical attacks as well as magical ones.

The above description is not the only way to secure a public circle against magical tampering, but it makes the point that it is well within the capabilities of a city to maintain such a circle with minimal risk of having it dispelled by either random acts of magical vandalism or a dedicated antagonist.

Physically disrupting the runes in the sigil sequence (using, for example, a pickaxe) will prevent it from functioning, effectively destroying it. Obviously, this isn't as easy or stealthy as casting dispel magic from 120 feet away, but this method is available to anyone who can swing a pickaxe. Any circle must be protected against physical attacks as well as magical ones.

The above description is not the only way to secure a public circle against magical tampering, but it makes the point that it is well within the capabilities of a city to maintain such a circle with minimal risk of having it dispelled by either random acts of magical vandalism or a dedicated antagonist. The guiding principle is that an unattended teleportation circle protected only by spells and other magic wards is not feasible, nor would any city want such a circle to exist. The circle must be guarded by people, not just spells. The best modern analogy might be an international airport: people can arrive from anywhere in the world and the associated infrastructure is expensive and delicate, so the security practices must reflect that. (Let's ignore the questionable effectiveness of the security at real-life airports. Your fantasy security can be as effective or ineffective as you want it to be.)