Familiar sizes.

[Aussiehams]

G'day all.

How do most DMs rule on familiar sizes? I was thinking a spider would be good for crawling under doors etc. for some good scouting/sneaking. But the spider is tiny, which is the same size as the owl.
I'm no expert, but I've never seen an owl as small as a spider. Or are the spiders giant huntsman's or something?

Is their any reason beside looks to not have an owl?

[JumboWheat01]

Spiders in most RPGs are not exactly the dime-sized things people have roaming around their house most of the time. They be huge. "Kill it with fire" huge.

If you're in a more aquatic adventure, an amphibious familiar would probably be the most useful mechanically, though yeah, outside of Chain Warlocks, if you're going for familiar optimization for some odd reason, there's really no point in choosing others.

[nickl_2000]

Sure, there are plenty of settings/locations where an owl would be very odd. However a rat would for right in.

In waterdeep a flying familiar may end up a snack for the griffins in the griffin calvary as well.

[iTreeby]

Size is wierd in this edition, there is no size smaller than tiny. if the spider has 2 strength, it can carry 15 pounds of gear so it can't be that small...

There are a few spells that interact with the spider familiar differently than other familiars. One is web, which the spider is immune to (though any flying familiar might also be able to avoid it) and can thus deliver touch attacks to creature caught in the web. Another spell is giant insect (which is only good if your druid friend has a 4th level spell and concentration to burn and even then...) which I've never heard about anyone using ever.

1) convince your party to have a total of 3 spider familiars through magic initiate or whatever
2) someone casts giant insect to transform the spiders into giant spiders
3)???
4)profit

If you can convince some people to do this, maybe you can milk them for venom or make special saddles and ride them around? Craft stuff from their silk? Barding?

It's not optimal but there are some spider things you could do if you really wanted to.

[Dork_Forge]

To not have an Owl in general? Yes, for example bats get Blindsense which can be a great resource for a low level party especially if the caster is a non Darkvision race.

Owl's are generally the most recommended for combat because of flyby, but if your primary use is going to be scouting then a lot of familiars are great options.

[Greywander]

I was thinking a spider would be good for crawling under doors etc. for some good scouting/sneaking. But the spider is tiny,

Man, I just made a thread about this not that long ago. I think the conclusion we came to are that these "spiders" are massive things, probably with something like a 1- to 3-foot legspan (since they occupy a 2.5x2.5 square). Also remember that one size up from Tiny is Small, which means Gnomes and Halflings are valid grapple targets for any Tiny creature.

I still think we need sizes smaller than Tiny.

Is their any reason beside looks to not have an owl?

To not have an Owl in general? Yes, for example bats get Blindsense which can be a great resource for a low level party especially if the caster is a non Darkvision race.

Owl's are generally the most recommended for combat because of flyby, but if your primary use is going to be scouting then a lot of familiars are great options.

I like to point out that ravens can use Mimicry to create distractions. Depending on how permissive your DM is, they might even let your raven talk; IRL ravens are every bit as good at mimicking human speech as parrots are. Mimicking speech doesn't allow them to understand languages, or to form coherent sentences on their own, however, though you might be able to telepathically assist them in those departments.

I also feel like ravens are a bit more ubiquitous than owls are. They're everywhere. Maybe things were different in medieval times, but around where I live I rarely see owls but frequently see crows (which aren't ravens, but are related to ravens, so close enough). And it's not because owls don't live here, I just don't see them.

[Xenken]

Owl is a good generic pick but there's definitely more to consider.

As for sizes, I imagine most DM's picture Spider as just, well, a regular spider, and handle doors and such accordingly for it when compared to the Owl, even if they're in the same size category. The "AHH IT'S AN RPG KILL IT WITH FIRE" kind of spider is closer to the Giant Wolf Spider imo.

[Greywander]

As for sizes, I imagine most DM's picture Spider as just, well, a regular spider, and handle doors and such accordingly for it when compared to the Owl, even if they're in the same size category. The "AHH IT'S AN RPG KILL IT WITH FIRE" kind of spider is closer to the Giant Wolf Spider imo.

There are spiders in real life that can reach a legspan of 1 foot, so it wouldn't need to be something too fantastical. The spider stat block is probably referring to something like a larger tarantula-esque spider, maybe the size of a cat. Definitely pushing the upper limits for what we'd expect of a mundane spider, but still within the realm of plausibility.

I think the question, though, would be if you could choose to conjure a familiar who was a tiny jumping spider, only a couple of millimeters across? And the answer, I would think, is that yes, you can, but there isn't really a stat block for this kind of creature. Again, I think we would need to extend the size system with size categories smaller than Tiny in order to make this work.

[Addaran]

My DM let me have a really tiny normal spider. Since familiars can't attack (except warlock) the stat block's damage isn't important. I also didn't try to make the familiar drag stuff or do anything a normal spider couldn't do, since the stat block is normally for bigger spider.

[False God]

I always rule that "magical familiars" are a bit bigger than usual but average around the size of a large rat.

That's not to say spiders and rats and pixies still can't sneak through small holes and stuff, but you need at least a cat-door sized hole.

Also: D&D sizes are hilariously useless for measurements especially on anything outside of "medium".