Detect Magic as a Secret Language?

[SangoProduction]

OK, I know I do a post like this almost every year, but I was thinking about how special senses could have their own unique languages specific to those senses. Like how tremorsensors could be really into tap dancing as a form of poetry.
And this time, Detect Magic fell under my gaze. It allows you to detect lingering auras of spells and items.

The first problem I noticed was the relatively low bandwidth. Even though you have 8 schools, allowing each character to have 8 possible states (compared to binary's 2), it generally is going to take 6 seconds between each character. This makes it useful as a code form, but really limited, compared to say, an alphabet. And it would probably be pretty excruciating for real-time conversation. (Unless, of course, it was instead a code language, with much denser meaning per character. Very much akin to binary or kanji.)

The second issue is one of false-positives. Obviously, anyone casting would leave an aura, not just someone trying to communicate something. But this could be worked around by requiring "start" and "end characters. Preferably those that do not normally follow a typical caster's order. Just as an example, a message could be defined by having 2 divinations, one at the beginning of the message and one at the end. Which could still lead to false positives if you encounter a scry-and-die who's confirming their kill. But those would be high level auras.

Third, and perhaps most importantly: Auras do not appear to have a "sequencing" to them, by default. So a message in Mage Speak would be closer to using Roman Numerals than modern math. An X II X would be equivalent to IXXI or XX II. This substantially reduces the number of messages that could be conveyed per number of auras.
But as this is a "in the weeds" detail, it could be concluded that someone who knows Mage Speak might be able to actually tell the relative sequence of the auras, which would also help to rule out false positives.

Fourth is spell capacity, and durability of the message. Cantrips would be the most accessible method of producing auras, since in pathfinder, they are freely cast-able, and all wizards have all cantrips. But it only lasts for less than a minute. And even a 7th level spell's aura only lasts at most an hour.

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So, there is actually a way to address all those problems, and that's Magical Ink! Yeah, a magical item that can produce ink that holds a specific aura. Perhaps you would need multiple different vials, each for a particular aura, or maybe a stronger ink that is able to change its aura as it's being written with.
This would allow for a durable, high capacity messaging system with very little chance of a false positive. And as a coded language, it would be relatively high bandwidth (after it's written), though a poor method of real-time communication. And best of all, it could function as an ink, it would allow you to write inconspicuous letters with messages coded into the ink itself, rather than the message.
It would also obviously give sequencing to the aura, restoring the lost information density.

Now, the specifics of this ink would no doubt be down to the crafters themselves. It is said that a master mystic alchemist could make ink that last for years, and controlled by thought. While others require command words or mimic the most powerful aura at the time of writing, and yet others only produce a single aura, and last for mere days.

So for some example coded messages...

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Divination - Transmutation: This could represent "Seek Change". Divination signifies seeking or understanding, and Transmutation signifies change or transformation. Depending on context (which could be conveyed in the mundane text), it could mean to attempt to change someone's mind, or change location. Although one would think a more specific message involving Enchantment or Conjuration (teleportation) would be desired.

Conjuration - Evocation: This could mean "Bring Force". Essentially detailing the need to get help, and be ready for a fight.

Divination - Illusion: Could mean "Beware of Deception." Self Explanatory.

Necromancy - Enchantment - Evocation - Divination: "Revive operation at sunrise". Necromancy could be a metaphor for revival, with Evocation-Divination as an accepted form of "sunrise", in a long message, while Necromancy-Divination could be "sunset" in the context of a long message.


And surely a bunch of 18-intelligence magic-college grads who wield the power of the universe in their finger tips, and have way too much time on their hands would be able to come up with much denser, more conditional messaging systems.

[Elkad]

You don't have to cast spells to transmit.
You could do something like morse code or an ASCII alphabet by showing or indicating items with the correct aura.

To a muggle, it could be any 2 (or more) random objects.

Communicating participants just rearrange checkers pieces, or juggle apparently-identical balls, or tap idle patterns on their enchanted wineglass and napkin.

Imagine a deck of cards (minimum 8 cards, no real upper limit). Each card carries a specific aura of the 8. When you shuffle, the auras also shuffle, but independent of the cards themselves. The message sender shuffles, then deals a bunch of pairs onto a table, each pair is 1 of 64 characters.
And of course you could include a transposition cipher inside that, or code words, just as with any other written language.

To an observing Muggle, they'd be trying to determine the pattern in the displayed faces of the cards. But really that Two of Cups was evocation last shuffle, and it's abjuration this time, so it's value changed.

[Telonius]

8 possibilities - you can do a lot with a scale.

[Rebel7284]

Okay, long time programmer here, some thoughts on this system.


Magical areas, multiple types of magic, or strong local magical emanations may distort or conceal weaker auras.

So it sounds like, similar to issues in real computing, too much data density can cause issues. You can avoid some of that by making all objects with the same aura strength which makes your system a little more reliable but less data dense.

With person-to-person communication, it's a bit slow. You can certainly hold up a few objects at a time and then read each "word" or two that way every 18 seconds. Something like a wall with rows of skulls enchanted via Skull Talisman to radiate various schools can communicate a fair amount more, but again, the signal to noise ratio caused by multiple types of magic is up to your DM.

Question, can detect magic detect the "universal" pseudo school?

So your options:
1. maximum cost, maximum data density: Base 33 each object can represent one of 4 strengths of 8 schools + non-magical, essentially a character per object. However, this can run afoul of both strong auras interfering AND different types of magic interfering.
2. low cost, average density: Base 9 each object can represent a cantrip of each school or non-magical. Only runs afoul of the multiple types of magic, but less types and is cheaper.
3. medium cost, low density: Binary. Each object is either non-magical or enchanted by a single school. Should avoid the density issues altogether, although your DM may still add limits to how many spellcraft checks you can make at a time.

Option 1 is useful for real time communication where a high level character may indeed carry a bunch of scrolls of various schools anyway. Reasonable secret language.
Option 2 seems pretty useful for small static writing/puzzles
Option 3 could be useful for storing a LOT of data, but takes a lot more objects and more time to encore or decode making it WAY slower.

[SangoProduction]

Did not ever see that aura interference deal before. That certainly does complicate things.