Do familiars count as companions / significant creatures for the purposes of dying rules?

[AffenMann20000]

According to the CRB p. 479:
"Player characters, their companions, and other significant characters and creatures don’t automatically die when they reach 0 Hit Points. Instead, they are knocked out and are at risk of death. At the GM’s discretion, villains, powerful monsters, special NPCs, and enemies with special abilities that are likely to bring them back to the fight (like ferocity, regeneration, or healing magic) can use these rules as well."

What exactly counts as a companion feels a bit vague to me.
Animal companions obviously do, but as far as familiars are concerned its uncertain.

There are companion items, which "have the companion trait, meaning they function only for animal companions, familiars, and similar creatures." (p. 604) but as far as I know there are no creatures that have the companion trait. So, are all creatures that could use companion items companions?

The easy answer would be to say "oh, it's the GMs decision whether familiars have dying rules or not" but ideally, I would like to know what the RAW/RAI answer is.

Thank you

[YuriP]

This is an interpretative rule. Both GM and players decides what's is significant characters for them. So it's bit easily to interpret that familiars are included because they are significant characters for the players characters.

[pauljathome]

Any GM who did NOT apply the "dies at 0 hp rule" to animal companions and familiars is a GM that I would never, ever play with again. People tend to grow attached to their pets :-)

[breithauptclan]

Yeah, I see 'companions' to be a general term for any permanent additional characters that are part of a player's character. So minions like familiars and animal companions, hirelings, bonded animals, and similar. 'Other significant characters' would be any NPC visitors to the party. So things like the NPC that is the focus of the escort mission that the players are currently on.

[Themetricsystem]

Yes, 100% and without a doubt, this isn't even up for debate either.

CRB: Hero Points wrote:

You can spend a Hero Point on behalf of your familiar or animal companion.

Link

[YuriP]

pauljathome wrote:

Any GM who did NOT apply the "dies at 0 hp rule" to animal companions and familiars is a GM that I would never, ever play with again. People tend to grow attached to their pets :-)

I only think this is a heartless GM! kkkk

[Gizmo the Enemy of Mankind]

AffenMann20000 wrote:

There are companion items, which "have the companion trait, meaning they function only for animal companions, familiars, and similar creatures." (p. 604)

In addition to the section on companion items that you already referenced, there is also a sidebar (find it here) on page 96 Secrets of Magic that classifies familiars as companions.

SoM p96 wrote:

TARGETING COMPANIONS AND EIDOLONS

Some spells in this chapter can affect the caster's companion or eidolon. When “companion” is used in a stat block, it refers to animal companions, familiars, and future types of companions—such as construct companions—but not eidolons. Some spells are even more specific. For example, if the spell says, “Targets your familiar,” you could cast it only on a familiar, not other kinds of companions. If you Cast a Spell that can benefit only a type of creature you don't have, such as Casting a Spell that can target only an eidolon when you don't have an eidolon, the spell does nothing.

That's two pieces of evidence to suggest that, yes, familiars are companions.