Detect Magical Residue Spell
Detect Magical Residue is a third-party legacy divination from Crime and Punishment (Atlas Games, 2003). It extends ordinary Detect Magic into magical forensics: weak traces linger for hours or days, and a trained investigator can study an aura for clues about the caster who created it.
At a Glance
| School | Universal |
|---|---|
| Original level | Inquisitor 1, Sorcerer/Wizard 2 |
| Casting Time | 1 action |
| Components | V, S |
| Range | 60 feet |
| Area | Quarter-circle emanation from the caster |
| Duration | Concentration, up to 1 minute/level |
| Saving Throw | None |
| Spell Resistance | No |
| Source | Crime and Punishment, Keith Baker, Atlas Games, 2003 |
Detect Magical Residue by Edition
5.5e / 2024 — No Direct Official Equivalent
There is no official 2024 spell that reproduces this forensic aura-reading system. Modern Detect Magic detects active magic and magical auras but does not normally reconstruct days-old traces or profile the original caster in this way.
5e / 2014 — No Direct Official Equivalent
The 2014 rules likewise have no direct Detect Magical Residue spell. Treat this as legacy third-party investigative magic rather than an expanded core Detect Magic rule.
Pathfinder 1e — Third-Party Conversion Only
The original Spellcraft-based procedure adapts easily to PF1e, but Detect Magical Residue is not a core Pathfinder spell. Any PF1e use should remain labelled as third-party material.
Original d20 Rules
The spell works broadly like legacy Detect Magic but detects residual auras for much longer and permits deeper analysis.
| Aura | Spell level | Item caster level | Residue lasts |
|---|---|---|---|
| Dim | 0-level | — | 30 minutes |
| Faint | 1st–3rd | 1st–5th | 6 hours |
| Moderate | 4th–6th | 6th–11th | 24 hours |
| Strong | 7th–9th | 12th–20th | 4 days |
| Overwhelming | Artifact or greater | Epic/divine-scale | 16 days |
After studying an aura for three rounds, the caster can spend two additional full rounds making one of the following checks.
| Information | DC |
|---|---|
| Confirm whether two auras came from the same caster | 10 |
| Determine spellcasting class/tradition | 10 |
| Determine magical specialty or divine patronage | 15 |
| Determine time of casting | 15 |
| Estimate caster level | 18 |
| Determine species | 20 |
| Read sex/gender information encoded in the magical trace | 25 |
| Estimate age | 25 |
| Read “nationality” in the original source | 30 |
Failed checks can be retried while time remains, and the original rules permit taking 20 if the spell lasts long enough.
Misdirection: a false aura created by Misdirection is normally read as genuine. Beating the relevant check by 10 or more reveals both the false reading and the underlying actual aura.
What Changed?
- The spell is now clearly identified as third-party legacy material.
- No invented 5e/2014 or 5.5e/2024 mechanics are supplied.
- The aura-duration and Spellcraft tables are preserved.
- “Nationality” and similar impossible deductions are treated as supernatural information encoded in the aura, not mundane biology.
- Divine-specialty language is framed around patronage and magical tradition rather than any one real-world religious institution.
Using Magical Residue in Investigations
The spell is strongest after magical crimes: a teleportation, enchantment, ward, scrying attempt, summoned creature, cursed object or spell duel. It can tell investigators that the same caster was present at two scenes, estimate how powerful that caster was, and distinguish a fresh trace from one several days old.
It should provide leads rather than certainty. Misdirection, deliberate contamination, multiple casters, overlapping auras and unfamiliar magical traditions can complicate the reading.
Related Magic
Source and Provenance
Source: Crime and Punishment
Author: Keith Baker
Publisher: Atlas Games
Published: 2003