Is Polymorph responsible for the lack of high CR beasts?

Yunru · Oct 17, 2018

So I was working on a CR 20 beast, when I realised something.
I had to make it CR 21. Because if I didn't, level 20 characters could be Polymorphed into it.

Could it be that the reason there are no beasts beyond CR 8 is to stop Polymorph being too effective for a 4th level slot?

Just idle speculation.

Jester David · Oct 17, 2018

If I had to guess I’d say it was because beasts are *mostly* based on real world critters or modifications thereof, which makes them inherently less powerful and deadly than a giant or a midsized dragon.
Even going prehistoric and dinosaurs doesn't get you to double digit CRs.

What does a mundane nonmagical beast look like that is over twice as tough and deadly as a T-Rex?

Yunru · Oct 17, 2018

Jester David said:
What does a mundane nonmagical beast look like that is over twice as tough and deadly as a T-Rex?

Well for mine, it's a hydrokinetic.
After all, the definition of non-magical is a bit... wooly? In DnD.

MonkeezOnFire · Oct 17, 2018

High level monsters typically also get more supernatural abilities in order to keep up with the capabilities of the adventurers. You can scale up the numbers on a bear so that it will be CR 15, but even then it still won't pose as much of a threat as other monsters at that CR. And once beast like creatures start to get supernatural abilities it usually pushes them into the monstrosity category.

The phase spider is a good example of this. It's considered a monstrosity while a regular giant spider is a beast.

Jester David · Oct 17, 2018

Yunru said:
Well for mine, it's a hydrokinetic.
After all, the definition of non-magical is a bit... wooly? In DnD.

Anything magical would be a monstrosity. Beasts are mundane. Stuff that wouldn’t be out of place in the real world. Cryptids are as weird as you can get.

Yunru · Oct 17, 2018

Jester David said:
Anything magical would be a monstrosity.

Citation?

Also: Man how I hate 5e's categorisation. Unicorns aren't even Fey any more.

Jester David · Oct 17, 2018

Yunru said:
Citation?

Also: Man how I hate 5e's categorisation. Unicorns aren't even Fey any more.

The description of beasts in the Monster Manual on page 6 reads:
Beasts are nonhumanoid creatures that are a natural part of the fantasy ecology. Some of them have magical powers, but most are unintelligent and lack any society or language. Beasts include all varieties of ordinary animals, dinosaurs, and giant versions of animals.

It does say they can have magic, but the vast majority do not. Winter wolves might be the sole exception.
Beasts are part of the ecosystem. Anything CR 15+ is tricky to fit into a food chain.

It’s doable. But it’s probably easier to just make it a monstrosity...

Yunru · Oct 17, 2018

Yeah, I made mine a sea creature because everything's bigger in the surf.

But they left themselves plenty of room to work with, but chose not to fill it.
Only thing I can think of is for balance, which means the Druid and Polymorph.

Jester David · Oct 17, 2018

They also haven’t been inventing many new creatures. Most monsters we’ve seen have existed in past editions and are just updated; there are few dangerous beasts that work best as beasts.
They haven’t started gridfilling yet and creating new high CR beasts solely to add new high CR beasts.

MechaTarrasque · Oct 17, 2018

I think the craig cat (from storm king's thunder) is the only magical beast*, and that is primarily a defensive ability against spells.

It seems like they could make Legendary beasts and include in the entry that polymorph/shapechange/wild shape based on the LB only gives you the regular beast. They could pretty easily create higher CR beasts that way without unintended consequences.

* from WotC, Tome of Beasts has a lot of them, including, if my memory hasn't failed me, a dragon-looking one with a breath weapon and a gaze attack.

Not that this is official WotC, but the Ixalan Planeshift had a CR 10 legendary T-rex, Gishath, Sun's Avatar.