Is lifesense a precise sense, or imprecise?

Question

The question has come up in one of my chats, and I could not find an answer after a search of the Pathfinder Roleplaying Game Core Rulebook and Bestiary for 'precise' or 'lifesense'.

Aiudara wraiths (Pathfinder 150: Broken Promises) and various other undead (such as the Bestiary's astradaemon, dullahan, nosoi, morrigna, and wraith) have an ability called lifesense, often with a listed range of 60 feet.

The general entry from the Ability Glossary in the Bestiary notes, of lifesense,

Lifesense allows a monster to sense the vital essence of living and undead creatures within the listed range. The sense can distinguish between the positive energy animating living creatures and the negative energy animating undead creatures, much as sight distinguishes colors.

Meanwhile, the nosoi and morrigna psychopomps and the basic wraith call out in their statblock,

Lifesense (divination, divine): [Wraiths sense/A psychopomp senses] the vital essence of living and undead creatures within the listed range.

... the Aiudara wraith makes no such mention. Neither of the definitions that actually exist offer any insight into how to actually use the ability in play, though, where the rest of the game takes great care to distinguish between precise and imprecise senses.

Is lifesense precise or imprecise, and where would I turn for the general rule covering this situation?

Answer 1

Probably Precise

@curious_penguin does have the closest thing to a general rule I know of. However, lifesense gives us several hints it is precise, even in the Aiudara Wraith.

First hint is from the description of lifesense that you quote:

... much as sight distinguishes colors.

This indicates that the developers are already thinking of this in terms of being a precise sense.

Second, this lines up historically with lifesense being the Pathfinder 1e equivalent of a precise sense. Specifically, PF1e lifesense is similar to PF1e blindsight which is very clearly described in precise sense terms.

Third, there are several creatures that specify that their version of lifesense is imprecise: the Lion Visitant (AP spoiler), Iffdahsil (AP spoiler), and, importantly, the Meladaemon, which is from a Bestiary (and so is less prone to error). Importantly, if Lifesense is vague, then the Soul Slime (AP spoiler) has no precise sense at all! I have never seen a callout that specifically mentions "lifesense (precise)", which is what you'd expect for e.g. the Soul Slime if the assumption was that lifesense was vague or imprecise.

Answer 2

It probably is a vague sense.

Pathfinder Roleplaying Game Core Rulebook has a paragraph on vague senses and at the end of it it says:

Pathfinder's rules assume that a given creature has vision as its only precise sense and hearing as its only imprecise sense.

Going off this I would argue that, if not explicitly stated, a sense is vague.