Suppose I plan to learn the teleportation circle spell, or another spell that can use teleportation circles, some time in the future, but I don't currently know any such spell (or have one in my spellbook, if I'm a wizard). Can I start collecting known sigil sequences now and then use them once I learn the spell, or is knowledge of the spell a prerequisite for comprehending the sigil sequences?
For a specific example, would the following sequence of events be possible?
- Visit a town and learn the sigil sequence for a teleportation circle there.
- Leave the town and go adventuring.
- Learn the teleportation circle spell during the course of my adventure (having not previously known any teleportation spells)
- Use the spell to return to the teleportation circle in the town whose sigil sequence I had previously learned?
Best Answer
It's up to your GM
The details of learning sigil sequences is entirely absent from the rules. Apparently this was intentional on the part of the developers so that a GM can limit access to teleportation circles in areas the GM does not which to be accessible at a given time. This is discussed by Jeremy Crawford on Dragon Talk on 7/23/18.