Spell Name: Magic Mark

School: Enchantment

Casting Time: 1 Minute (Ritual)

Range: 60 feet

Duration: Until dispelled

Component: V, S

You gesture at a number of objects you can see within range that fit within a 15-food radius sphere. This spell puts an invisible mark upon the objects that reveals itself when in the area of a detect magic spell. You choose the design of the mark, and can mark up to 30 Tiny objects, 20 Small objects, 10 Medium objects, or 2 Large objects.

At Higher Levels: Whenever you cast this spell using a spell slot of 2nd-level or higher you can mark up to 15 additional Tiny objects, 10 additional Small objects, 5 additional Medium objects, or 1 additional Large object for every slot level above 1st.

An example of this spell happened in my D&D campaign.  The Mayor of a large seaport city was suspected of treasonous collaboration with a Lawful Evil Queen Goldstein Maul that ruled an oppressed land named “Iron Isle”, so named for the profitable iron mines on the island.  By deceit and treachery, she gained ownership of these iron mines; selling refined iron to evil aligned nations to create useful tools, armor, and weapons.  Queen Goldstein Maul would not sell iron to any good aligned nations.

Harper agents found out that the Lord Mayor was getting richer far faster than his income would normally allow him to be.  Harper agents already knew from the evidence they collected that the Mayor is a smooth-talking liar whose name is “Goodheart Truesdale”.

Thus, the Harpers sent my PCs disguised as tax collectors who sneaked into the Iron Isle.  With tax collector uniforms and believable appearing, yet faked documents; they found a caravan of wagons used by national Queen Maul’s tax collectors.  They were given permission by the caravan guards and low ranking tax collectors to inspect the tax money that they had collected.  In the wagons, my PCs marked many of the gold coins collected with the coin marking spell.

After a few months, in the PCs home nation, they asked to see the Mayor’s private home vault; with an excuse to find counterfeit coins.  When they cast detect magic on the coins, a few lit up with the now visible symbol.

The Mayor, without a logical excuse as to why he had the marked coins from the Iron Isle, confessed that he was working with thieves, along with the evil queen, to sell his city’s citizens into slavery to work the mines of the Iron Isle.  After the Mayor was sent to prison, the nearby good aligned nations invaded the Iron Isle.  The night before the invasion, my PCs burned six large catapults that guarded the island’s only harbor, Maritime City.  The invasion successfully liberated the island from Queen Goldstein Maul.

These successful adventures gave my player characters a great deal of fun, experience points and money, while gaining much positive fame (useful for charisma [persuasion] checks) from good people and their leaders; while gaining infamy with evil people and their rulers.

Two thoughts:

1. This doesn’t seem like it should be an Abjuration spell. Abjuration is all about protecting people and things, or warding areas. I could see making this spell in the Illusion school if the marks are illusory. I could see making it in the Enchantment school because the spell literally enchants the the objects a little bit. I could even potentially see an argument for Transmutation if the spell actually alters the objects in some way. But not Abjuration, it just doesn’t fit.
2. The only spells that get more powerful based on a caster’s level are cantrips. It would make more sense, as a 1st-level spell, that it should mark more objects when the spell is cast at higher levels instead.

My inspiration for this D&D spell came from the 2023 movie, Dungeons & Dragons: Honor Among Thieves.

Simon: You’re quick to call us failures, what about you Ed?

Edgin: I’m the champion of failures; I lost everything that mattered to me. You know what killed my wife? I did, I decided we deserved a better life. I didn’t know Red Wizards marked their treasure. I brought them to our door. I didn’t even have the good luck to be there.

I asked myself how the Red Wizards marked their treasure.  It was not a physical mark, so I decided that it was a magical mark that could be removed.  I saw no such D&D spell listed to magically mark money, so I invented one.

Quote from Dances_with_Unicorns >>

My inspiration for this D&D spell came from the 2023 movie, Dungeons & Dragons: Honor Among Thieves.

Simon: You’re quick to call us failures, what about you Ed?

Edgin: I’m the champion of failures; I lost everything that mattered to me. You know what killed my wife? I did, I decided we deserved a better life. I didn’t know Red Wizards marked their treasure. I brought them to our door. I didn’t even have the good luck to be there.

I asked myself how the Red Wizards marked their treasure.  It was not a physical mark, so I decided that it was a magical mark that could be removed.  I saw no such D&D spell listed to magically mark money, so I invented one.

 
Cool. It’s an interesting spell, and you’ve left its applications broad enough for it to be useful in a myriad of situations. I would just change which school of magic it belongs to and how it scales from by caster level to spell level so it sits more in line with how other spells are written is all.

Do you have any suggestions on how to scale that spell by caster level?  What about marking ten items per level of the spell caster?  10 items at level one, 20 items at level two, 30 items at level three and so on.

Quote from Dances_with_Unicorns >>

Do you have any suggestions on how to scale that spell by caster level?  What about marking ten items per level of the spell caster?  10 items at level one, 20 items at level two, 30 items at level three and so on.

 
As I wrote in my one of my previous posts, only Cantrips scale by caster level, not regular spells. Regular spells scale by spell level. So one would have to cast the spell at a higher level than 1st to have it scale at all, otherwise, no matter what level the caster is, if it is cast using a 1st-level spell slot, it would always only ever affect the same maximum number of items. I wouldn’t make it a cantrip, it would be too abusable as a cantrip. I would keep it as a 1st-level spell and have it affect, say, maybe 20-30 Tiny objects. Then, when cast at a higher level it would add 10-25 more Tiny objects per level of the spent slot.

However, if you insist on having it scale based on caster level for some reason, and do decide to make it a cantrip, then the answer is simple because cantrips do not scale every time a caster goes up in level. Cantrips only scale when a character hits 5th, 11th, and 17th levels. So if the item affects 10 Tiny objects as a base cantrip, then it wouldn’t increase again until the character hits 5th level when it would increase to 20 Tiny objects, then 30 at 11th level, and finally 40 at 17th level.

But as I stated earlier, making this a cantrip would probably be too much. Cantrips are cast for free. With this spell even a1st level spellcaster could mark almost everything in sight in a matter of just a couple of hours. I would keep it as a 1st-level spell instead. I might consider making it a Ritual spell so that it could still be cast for free, but instead of being able to mark 100 objects every minute, it would take them 10 minutes to mark 20-30 objects for free, and if they want to do it faster than that it’ll cost them spell slots to do it.

Please review the edits that I made to my first post, according to your suggestions.  Suggest any additional edits that come to your mind.

Spell Name: Magic Marking Spell

School: Ritual

Casting Time: 1 Action

Range: 60 feet

Duration: Until dispelled

Component:  V

Number of Tiny Objects marked:  The caster can mark 20-30 objects every 10 minutes for free, and if they want to do it faster than that it’ll cost them spell slots to do it.

This spell marks any type of coin or other object with a one inch tall, invisible “X” symbol.  These symbols will glow softly in the range of a Detect Magic spell.

Ritual isn't a school of magic. I agree with IamSposta that this should be school of Illusion or Enchantment. 

This spell seems to be very similar to illusory script. I'd keep the bits about marking with a symbol that can be seen with detect magic but would have the mechanics similar to illusory script, where it's a 1 minute casting time, but also a ritual making it a no spell slot 11 minute casting time, range of touch. Perhaps 1 casting (1 minute w/ a spell slot, 11 minutes w/o) could mark up to 30 tiny objects, 10 small objects, 4 medium objects, etc etc.

Try this:

Magic Mark

1st-Level Enchantment

Casting Time: 1 Minute (Ritual)

Range: 60 feet

Duration: Until dispelled

Component: V, S

You gesture at a number of objects you can see within range that fit within a 15-food radius sphere. This spell puts an invisible mark upon the objects that reveals itself when in the area of a detect magic spell. You choose the design of the mark, and can mark up to 30 Tiny objects, 20 Small objects, 10 Medium objects, or 2 Large objects.

At Higher Levels: Whenever you cast this spell using a spell slot of 2nd-level or higher you can mark up to 15 additional Tiny objects, 10 additional Small objects, 5 additional Medium objects, or 1 additional Large object for every slot level above 1st.

Many thanks for editing and improving my Magic Mark manuscript.