D&D 5E Dragons that can polymorph into humanoids...

[Casimir Liber]

So quite commonly dragons (particularly gold, silver and bronze dragons) can change into a human(oid) form. When DMs incorporate this into their games...can dragons change into only one particular humanoid form or any humanoid form?

 

[Oofta]

In my game they polymorph into their human form, so one and only one. However, that's just my world's lore and has nothing to do with the rules. By the rules they just cast the polymorph spell.

 

[aco175]

I did not think this was a thing since they stopped using spells, but I always liked it for plot purpose. I would allow them to change into several forms. Maybe the older they get, the more they stick with one form.

 

[nevin]

i prefer a set form as the humanoid form. I would give a PC a set form if I let them have an inborn shapeshifting ability letting the dragon have more than that seems excessive.

 

[billd91]

I'm not aware of any limitation on the forms they can pick - as long as it's a humanoid or a beast. So they could have numerous alternate IDs in a variety of places.

 

[Oofta]

I did not think this was a thing since they stopped using spells, but I always liked it for plot purpose. I would allow them to change into several forms. Maybe the older they get, the more they stick with one form.

Ancient gold dragon for example can polymorph as an action. From the MM:

Change Shape. The dragon magically polymorphs into a humanoid or beast that has a challenge rating no higher than its own, or back into its true form...​

 

[Vaalingrade]

So quite commonly dragons (particularly gold, silver and bronze dragons) can change into a human(oid) form. When DMs incorporate this into their games...can dragons change into only one particular humanoid form or any humanoid form?

I have them have favorites despite being able to turn into anything.

I also have it so because dragons naturally lack hair, they tend to have human modes with lots of or elaborate hair. They're also not all that good at paying attention to mortals, so they have odd or exaggerated proportions, like the drawings of a particularly talented child.

 

[Stormonu]

Yeah, I go with the one "face" (but could do elf, human, dwarf, etc.), but most that can change also are generally magical enough they could have access to Disguise Self if they need to further change their appearance.

 

[humble minion]

I was reading an old Dragonlance novel recently in which a dragon was experimenting with what humanoid forms she could change into. She could certainly choose some details of her humanoid appearance, but was frustrated because she could not become less than conventionally attractive, even when she wanted to take a form that was unremarkable and would not attract attention.

It's only one data point, from a long time ago with questionable/limited canonicity, but it was interesting...

 

[Sorcerers Apprentice]

In my game they polymorph into their human form, so one and only one. However, that's just my world's lore and has nothing to do with the rules. By the rules they just cast the polymorph spell.

Polymorph also doesn't say anything about whether you can transform into various individuals of each form, so it can be interpreted either way.