Weights and Measurements in Ravenloft

[Pizza]

Does each Domain have its own units of measurement?

[Mischief]

Does each Domain have its own units of measurement?

In-universe, probably, based on the domain's thematic origin. Ravenloft is already a mess of languages and currencies and calendars. I see no reason why units would be different.
As a system, kept in check by the developers' desire to keep things rules-simple.

[DustBunny]

Does each Domain have its own units of measurement?

Undoubtably.

Medieval Europe based its system off the old set of Roman standards. But when that collapsed, it wasn't very long before weights and measures drifted between countries, and even between regions in the same country. Ravenloft never had a centralized set of standards, so as each domain appeared it would bring its own set with it, resulting in a total mess.

The meta-game way we worked around it was to have the rule book measurements called the "Merchants Mile". Merchant groups roamed all over the world, had members from all over the place, and would regularly exchange good with each other.

So, to reduce the paperwork, they had an informal set of measurements and standards between them. A "merchants’ pound" in Richmoulet was equal to a "merchants’ pound” in Darkon. A "Merchants Mile" was a distance between two locations, allowing merchants to work out how long it would take goods to move between points, etc. As a result, travellers (and adventurers) also picked up on this as it was an easy way to have consistent travel plans and currency across domains.

Of course, converting local currency and weights from Merchants to local measurements created a lot of plot hooks and pitfalls. (Oh, the killer zombies are 10 stadia that way. Um that's 2 miles? 4? Damn, I wish I had the local history skill)

[Pizza]

Those merchant measurements sound like a good idea.

[Mistmaster]

My Core had the Olympian empire to bring a coommon language and a common metrical system.

[Mischief]

(Oh, the killer zombies are 10 stadia that way. Um that's 2 miles? 4? Damn, I wish I had the local history skill)

Local history? Who needs that? Just fire up Contact Other Plane and wait for Azalin to pick up.

[DustBunny]

Local history? Who needs that? Just fire up Contact Other Plane and wait for Azalin to pick up.

PC: *contacts plane* "Hey we're hunting zombies. What's the conversion of 10 stadia to miles?"
Az: "Zero" *click*
PC: "Huh, they hung up. Zero miles? But that's..."
Killer Zombies appear: "Raaar!"
PC: 'Oh."

[Joël of the FoS]

Local history? Who needs that? Just fire up Contact Other Plane and wait for Azalin to pick up.

PC: *contacts plane* "Hey we're hunting zombies. What's the conversion of 10 stadia to miles?"
Az: "Zero" *click*
PC: "Huh, they hung up. Zero miles? But that's..."
Killer Zombies appear: "Raaar!"
PC: 'Oh."

We miss a like button on these boards.

[Mischief]

Local history? Who needs that? Just fire up Contact Other Plane and wait for Azalin to pick up.

PC: *contacts plane* "Hey we're hunting zombies. What's the conversion of 10 stadia to miles?"
Az: "Zero" *click*
PC: "Huh, they hung up. Zero miles? But that's..."
Killer Zombies appear: "Raaar!"
PC: 'Oh."

We miss a like button on these boards.

I'm glad 5e kept the "Darklords can sense when someone in their domain is casting a spell that allows contact with beings from other plane, and can choose to make themself the spell's recipient, so that the Darklord becomes the one who is contacted." mechanic.

But it doesn't say that the Darklords know who is asking, what spell is being used, if they can disguise as the correct recipient, nor if they are going to have to answer a bunch of silly questions, ...

...so consider the pickle the Darklord might find themself in by man-in-the-middling the cleric using commune.

You contact your deity or a divine proxy and ask up to three questions that can be answered with a yes or no. You must ask your questions before the spell ends. You receive a correct answer for each question.

If anyone out there wants a short adventure plot hook or writing prompt, a Darklord accidentally zone of truthing themself and having to divulge something secret to an unknown party on the other end of the spell is a pretty good scenario.