Is there a Sorcerer/Wizard spell that divines a creature's rough level/CR/power?

[47948201]

Or something to that effect. Something like the Paladin spell *know greatest enemy*, which gives you a weak/moderate/strong/overwhelming aura for creatures based on their CR. Basically, a way for a wizard to get an idea for whether the party should fight or flee, without having to wait for someone to almost die.

(If it's a cleric spell instead then that's fine too)

(3.5e)

[Dimers]

I found three related spells quickly -- nothing that does the job as well as know greatest opponent, but they're a start. Spell Compendium has know opponent (clr3) and know vulnerabilities (wiz4/clr3), and Magic of Faerun adds know protections (wiz1).

[Firest Kathon]

Not a spell, but Pathfinder's Occult Skill Unlocks (https://www.d20pfsrd.com/alternative-rule-systems/occult-adventures/occult-rules/occult-skill-unlocks/) (open for anyone in a psychic casting class or with the Psychic Sensitivity (https://www.d20pfsrd.com/feats/general-feats/psychic-sensitivity) feat) allow you to detect a creature's class, level or HD using Knowledge(arcana) or Sense Motive. However, both uses take 10 minutes, so usually not fast enough to be done in combat.

[Powerdork]

If there's a method to use Sense Motive to read someone's power in terms of relative statistics (I recall reading about such a thing), then finding a way to boost that check would be great for your purpose.
Sorry I can't give more specifics, my 3.5 collection isn't huge and I'm away from it for the time being.

[Dimers]

If there's a method to use Sense Motive to read someone's power in terms of relative statistics (I recall reading about such a thing), then finding a way to boost that check would be great for your purpose.
Sorry I can't give more specifics, my 3.5 collection isn't huge and I'm away from it for the time being.

Good point! That's an expanded skill use for Sense Motive in Complete Adventurer, supported and improved with the Combat Intuition feat (same book) but usable without.

[Gruftzwerg]

Or something to that effect. Something like the Paladin spell *know greatest enemy*, which gives you a weak/moderate/strong/overwhelming aura for creatures based on their CR. Basically, a way for a wizard to get an idea for whether the party should fight or flee, without having to wait for someone to almost die.

(If it's a cleric spell instead then that's fine too)

(3.5e)

Is HD also acceptable? I mean there are many spells that have different effects based on HD, starting with simple things like Color Spray and spells like that.

A heightened Color Spray is always a good combat starter and brings more to the table than just checking the power.

Power Word Pain (1d6 dmg per round) is a nice check for single targets and quickly determines the HP of the creature. And it has no saving throw, which makes it a reliable check unless the target has spell resistance.

50 or less : 4d4 rounds
51-75 : 2d4 rounds
76-100 : 1d4 rounds

For the later/higher levels there are other spells with similar checks like Cloudkill.

Really, I would avoid using action for divination spells/skills when you can have similar infos with added effects/dmg to it.

[Goaty14]

Power Sight (MotW) is a 1st level Druid spell that determines the total HD of a creature. As HD scales faster than CR as levels, though, it ages poorly. Plus it's a druid spell, and not what you want.

Arcane Sight is a 3rd level Sor/Wiz spell that determines the highest level spell/SLA a creature can be cast, and can be permanencied as not to spend actions in battle. For anything that isn't a humanoid with full caster levels, it works poorly (an Efreeti can cast Wish, a 9th level spell, but is CR 8, and a level 20 ranger can cast 4th level spells but (should be) CR 20).