In my wanderings through the various Spelljammer related content in the old Dungeon and Dragon magazines, I came across an adventure that wasn't exactly a Spelljammer one, but included a friendly NPC that was an Arcane. The Arcane are blue skinned giants known for being sellers of magical artifacts of all types, including a near monopoly of spelljamming helms.
The adventure itself was an interesting read (maybe I'll work it into my Spelljammer game), but something unusual about it was that it had a couple spells at the end: Arcane Runes and Read Arcane Runes.
I decided to add them to my
playtest Spelljammer spells as wizard spells, and give them a little extra flavor. So, I present to you: my 5th edition adaptation of the spells from Dungeon magazine #53' "Clarshh's Sepulchre".
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Arcane Runes
4th level Alteration (ritual)
Casting time: Special
Range: Touch
Components: V, S, M (A pinch of dried and powdered lemon, which the spell consumes, and a stylus)
Duration: Permanent or until dispelled
Silently mouthing the words as you write, you inscribe a message or longer text, hidden invisibly within a scroll, book, paper, or parchment. It can be hidden within another text, such as a secret message hidden in a letter or an entire book hidden inside another book. For longer texts, a single Arcane Runes spell can be used, the casting time ending when you close the book or scroll you are working on.
The effect of the spell is not detectable with a detect magic spell, but can be seen by you and anyone designated during the casting of the spell and creatures with truesight.
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At first, this seems like a really nice, though complicated way to send secret messages, but there is a twist.
Arcane can see any text hidden by the spell, without even trying. (Don't tell your players this, or if you are a player, your character doesn't know this!)
This, of course, would be a carefully guarded secret. They would
gladly sell scrolls (probably at a discount, but not so much for one to
be suspicious), hoping to let it spread and increase the chance that
they could see something secret that could be profitable for them.
The knowledge of this spell would lead others to seek a way to see secrets hidden away by Arcane Runes, and some such wizard managed to create a way.
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Read Arcane Runes
4th level Divination (Ritual)
Casting time: 1 action
Range: Self
Components: V, S, M (A lit candle held behind the paper or parchment to be read and a magnifying lens)
Duration: Concentration, up to 10 minutes
Upon casting this spell, you are able to see all text hidden with the Arcane Runes spell as though you were designated by the caster to be able to do so. You are still required to understand the language that the hidden text is written in.
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And woe to the unfortunate fool that is found with this spell by an Arcane. Not only do they want their clients to feel secure in the knowledge that their messages are being kept hidden from prying eyes, but they want to be the only ones doing the prying. Depending on the Arcane, they might act curious about where you found the spell, and perhaps slip you some gold to remove it from your spellbook, but some might just skip to destroying you and everything you love for encroaching on their terf. Possibly without you ever knowing why or who.
You probably don't want to get on any giant's bad side, but definitely not one that buys and sells magic items for a living. You never know what they have on hand.