Recently I detailed the crime-investigation spells available in 5e D&D, and the takeaway is basically “do whatever you want, the authorities cannot track you down.”
Here are some new ritual wizard spells that might make things harder for PCs – or for the PCs’ elusive enemies.
Level 1: Identify Weapon. Duration: Instantaneous. While casting this spell, you touch a wound or a damaged area on a creature or object. You can visualize the weapon or object which inflicted the damage. Besides knowing its appearance, you are now familiar with the object for the purposes of the Locate Object spell. Countermeasures: This spell fails if the damage was inflicted by a creature’s natural weapons, including fists, or by spells.
Since this is a level one spell, any militia with any spellcasting at all can now trace murder weapons (or breaking-and-entering tools). The prevalence of this spell has the fun side effect of encouraging criminals (including PCs) to beat each other up instead of stabbing each other.
Level 2: Aura Print. Duration: 1 hour. You sense the unique, identifying aura of every mortal creature that you can see. (Undead, fiends, angels, and other immortals have no aura.) You can spend a minute making a written note of an aura’s properties. You or anyone with your notes will be able to recognize this aura if they see it again. Anyone consulting these notes is considered familiar with a creature for the purposes of Locate Creature and Scrying. If cast in a level 3 spell slot, you can see the aura of the last mortal creature who directly touched any physical object within 24 hours. Countermeasures: Nystul’s Aura can be used to create a false aura or mask an aura for 24 hours, or permanently wipe the aura from an object.
I made this spell low-level because fingerprinting is the bread and butter of police procedural investigations, and it should be available even to, say, the authorities in a medium town. It also pleases me to make Nystul’s Aura, a level 2 spell I’ve never seen cast, into an important counterspell.
Level 3: King’s Highway. Duration: 1 hour. While you are under the effect of this spell, all your Locate spells (for instance, Locate Object and Locate Creature) have their range extended, adding “anywhere on a well-patrolled, civilized road or path” (whatever civilized means in your setting). You know the distance and direction of the target. Countermeasures: none, except those that block divination spells. This spell is why fugitives skulk in houses, camp in the wild, jump over paths, and cross roads only late at night and after great hesitation.
I made this spell level 3 so that it would be available to medium-level casters. Even a town guard might have a relationship with a level 5 wizard to track stolen valuables with Locate Object. If the wizard is level 7, even better, now King’s Highway can be used on Locate Creature. (Note that King’s Highway synergizes with Aura Print.)
Level 4: Analyze Species. Duration: instantaneous. You learn the species of animals and plants that make up one non-living target object. For instance, you could determine that a wooden door was oak, the blood at a crime scene was a mix of human and elven, a corpse was a doppelgänger, or that a cake contained grain, chicken eggs, sugar cane, and vanilla beans. To identify exotic species, you make a Nature check against a DC chosen by the DM. On a failure, you can only determine an ingredient’s general type (aberration, or leafy plant, for instance). Countermeasures: Prestidigitation will clean up blood stains. Exotic and red-herring ingredients will complicate poison analysis.
At level 4, this is a reasonably high-level spell: if you don’t have a 7th-level wizard on hand, you might have to send evidence to a wizard’s lab in a big city.
Level 5: Teleportation Path. Duration: 1 hour. While concentrating on this spell, you can see the astral rifts left by teleportation magic. Any space that was the source or destination of a teleportation effect glows. If you cast Teleport while standing on such a path, you can follow the teleportation route without knowing its destination. Countermeasures: You can instead use this spell to obscure your teleportation route. While under this spell, you may make an Intelligence/Arcana check when you teleport. The result is the DC for people who try to use this spell to follow your path. On a failure, their teleportation spell fails and its casting is wasted.
I’m making this level 5 because it matches well with Teleport, level 5. Since it’s so high level, only royal advisors and arcane colleges are likely to have it available. (The Mage in the Monster Manual, who offers “counsel to nobles,” has one 5th-level spell slot and can’t cast this and Teleport on the same day.)
With these spells available, PCs have the tools to attack a D&D mystery like a police procedural, with evidence leading to evidence. “Wounds on the victim led us to a dagger at the bottom of the bay.” “Aura Prints on the dagger match those of a known tiefling felon.” “I’ll use King’s Highway to watch the roads. You go to the Mage’s Guild and find out if any tieflings used their teleportation circle. If so, trace the jump.” Each step along the way can be an adventure hook.
If you’re curious why I’m writing divination spells that are of most interest to NPCs: it’s because I’m currently running a heist-based city campaign. My players take note! From next session on, the target of your heist might have access to these spells.