D&D 5E Quick question re: monsters as PCs

[JPL]

Is there any kind of quick and dirty rule of thumb for what level of challenge rating corresponds to what level of PC?

I.e., if I wanted to throw a gold dragon wyrmling (challenge rating 3) into a PC group, what level should those other PCs be?

Just for one-shots, you understand.

 

[Cap'n Kobold]

Not really: CR is based on challenge for a single encounter, not entire days of adventuring.

I'd suggest comparing capabilities with a non-optimised PC character in an equivalent role. How powerful abilities like flight are going to be for this particular adventure is something that the DM is just going to have to eyeball.

 

[Fanaelialae]

I put together an equivalency table of my own. We've used it for a few years now, and it works fairly well. Note, however, that a few monsters (ie, pixies) don't convert well with this guideline. The chart is designed for monsters that are PC powered and have rolled stats and a class (good saves, proficiencies, etc). If I use a monster straight from the book, I treat its CR as being one step lower on the table.

Level - CR
1 - 1/4
2 - 1/2
3 - 1
4 - 2
5 - 3
7 - 4
9 - 5
11 - 6
12 - 7
14 - 8
16 - 9
18 - 10
19 - 11
20 - 12

 

[Sunseeker]

I put together an equivalency table of my own. We've used it for a few years now, and it works fairly well. Note, however, that a few monsters (ie, pixies) don't convert well with this guideline. The chart is designed for monsters that are PC powered and have rolled stats and a class (good saves, proficiencies, etc). If I use a monster straight from the book, I treat its CR as being one step lower on the table.

Level - CR
1 - 1/4
2 - 1/2
3 - 1
4 - 2
5 - 3
7 - 4
9 - 5
11 - 6
12 - 7
14 - 8
16 - 9
18 - 10
19 - 11
20 - 12

Based on the math I have done, this table is fairly accurate. However, PC classes are very fluid in their construction and its very easy for some (usually clerics and cruids even in 5E) to be valued at significantly higher CR. It's also worth noting that sticking classes on top of monsters can do unexpected things to them, I assume the OP plans to let this gold-dragon PC take levels eventually.

I will also also point out, dragons age up through the first couple stages fairly quickly. (I believe in 5E Wyrmling is 0-5 years?) So if your campaign has a lot of time passing in it, this is something to keep an eye out for as it can provide a significant boost to PC power.

 

[Quickleaf]

Is there any kind of quick and dirty rule of thumb for what level of challenge rating corresponds to what level of PC?

I.e., if I wanted to throw a gold dragon wyrmling (challenge rating 3) into a PC group, what level should those other PCs be?

Just for one-shots, you understand.

A gold dragon wyrmling has 60 hit points, AC 17, good stats, a single attack +6 dealing 9 (1d0+4) damage, and a "spell" it can cast about once every 3 rounds dealing 22 (4d10) fire damage against one or two monsters (its breath weapon).

Compare that to a 4th-level fighter, good stats, Defense fighting style, with greatsword with half-plate and feats... about 40 hit points (50-60 hit points with 1-2 uses of Second Wind), AC 18, a single attack dealing 11 (2d6+4) damage, or two attacks with Action Surge every combat or two dealing 22 damage. Plus all the other stuff the fighter gets from its subclass.

I'd say you could including the wyrmling as a PC with a 4th-level party, and it'd be pretty fairly balanced.

 

[Cap'n Kobold]

A gold dragon wyrmling has 60 hit points, AC 17, good stats, a single attack +6 dealing 9 (1d0+4) damage, and a "spell" it can cast about once every 3 rounds dealing 22 (4d10) fire damage against one or two monsters (its breath weapon).

Compare that to a 4th-level fighter, good stats, Defense fighting style, with greatsword with half-plate and feats... about 40 hit points (50-60 hit points with 1-2 uses of Second Wind), AC 18, a single attack dealing 11 (2d6+4) damage, or two attacks with Action Surge every combat or two dealing 22 damage. Plus all the other stuff the fighter gets from its subclass.

I'd say you could including the wyrmling as a PC with a 4th-level party, and it'd be pretty fairly balanced.

I'd place it at at least 5th level from all the other capabilities it has; Fire immunity, blindsight, extended darkvision, fast flight, swim speed and water breathing, weakness breath.

 

[JPL]

Good thoughts, all.

I would do something like this for a one-shot, so advancement is less of an issue. I would lean toward doing advancement on an ad hoc basis, maybe using the monster scaling rules as guidelines.

 

[Quickleaf]

I'd place it at at least 5th level from all the other capabilities it has; Fire immunity, blindsight, extended darkvision, fast flight, swim speed and water breathing, weakness breath.

I defer to your common sense, sir. 5th level makes sense.

 

[Ganymede81]

Take a look at the PC like humanoid monsters at the back of Volo's Guide.

The Conjurer and Enchanter are roughly modeled after 9th level PCs of those same schools, but are CR 6 and 5 respectively. Similarly, the Diviner is modeled as a 15th level wizard, but is listed as CR 9.

The Champion monster looks to be modeled after a level 15 Champion Fighter, but is listed as CR 9.

The Illusionist is CR 3, but is modeled after a 7th level Wizard.

There doesn't seem to be much of a pattern (they seem to balance based on the combat abilities as opposed to the PC level it was modeled after), but the CRs are always significantly lower than the appropriate PC level.

 

[ccs]

The quickest dirtiest method of comparison would be # of HD vs a fighter.
Maybe it's attack bonus/prof bonus.

AC doesn't matter much if it's within what a PC could achieve.
Niether does flight, datkvision, etc.
Nor does damage as long as its something a PC could achieve.