"I think Hydrogen is a rare element" and other science facts.

[BookTenTiger]

This reminds me of a 5e game in which we wanted to create lightning rods to help us battle a giant storm elemental. The DM said that technology like lightning rods didn't exist in the game world. I tried to point out that the cantrip "Shocking Grasp" worked better against opponents in armor so there was evidence that people in the world knew the attraction of lightning to metal. The DM wasn't convinced.

Which was totally fine.

Except that a few sessions later we wound up in a city in the Underdark that had levitating electromagnetic trains, electric lights, and guns.

I celebrate myself for exercising self control and only once asking, "Do they have lightning rods?"

 

[Voadam]

And if creating undead requires black onyx gems, why aren't black onyx gems contraband - and why aren't there search & destroy campaigns against them?

Undead are made in many ways. Onyx gems are only needed for certain specific necromancy spells as one method to create a few types of undead. Self replicating undead and death circumstances are usually way more common for things other than a necromancer's skeleton and zombie servants and even that depends on the edition for the spell components.

 

[Staffan]

Also know as "the suffocator"!

I mean, there is that, but there's also the fact that it makes no god damn sense.

Photosynthesis is (simplified) a reaction whereby a plant converts water, carbon dioxide, and light into glucose and oxygen. There's no way to turn CO2 into water, because there's no hydrogen in it. Unless of course you're splitting the carbon into four hydrogen atoms and a helium, but that doesn't seem to be within the realm of biokinesis. That's a thing high-level quantakinetics can do, but most of those are gone.

I'm fine with semi-magical biotech being able to run unrealistically efficient water reclamation systems. But I'd honestly be more comfortable with a doohickey that just magically made water appear than one that turned CO2 into H2O.

 

[Ruin Explorer]

There's no way to turn CO2

I mean, I was assuming it at least combined hydrogen and oxygen somehow, because yes unless we're doing actual alchemy...!

 

[Bohandas]

So I had a conversation about this once. We were discussing common, expensive material components for spells, ones that have set prices. 100 gp pearls, diamonds and diamond dust, that sort of thing. If there components are consumed by casting (as happens in many versions of D&D), what happens when, you know, the world runs out of them? Even though pearls are grown, there can't be that many of the right price. Or does inflation and local pricing matter? Does Identify require lesser pearls in the desert than it does in a sea town?

Do diamonds automatically replenish themselves, perhaps due to some rift to an elemental plane? Do the Gods do it? Will prices or even components change over time? Are these things bought and sold in a "mage marketplace"?

I'm thinking a combination of the elemental replenishment thing plus some of them being synthetic

 

[Bohandas]

An acquaintance was playing in a supposedly semi-realistic SF campaign, where they landed on the Sun. Until he had a quiet word with the GM.

That reminds me of the sci-fi movie Ad Astra, which billed itself as hard sci-fi, but had a sci-fi technobabble phenomenon that could have come from a 1950's b-movie or a lazily written episode of Star Trek driving the plot. They didn't land on the sun but they had a malfunctioning and/or sabotaged antimatter-based generator on a space station somehow causing power surges across the solar system that somehow got more intense the further that they were from the point of origin

 

[Whizbang Dustyboots]

I fairly recently had to explain the nigh-incompressibility of water and how the equalization of water pressure would work to the DM in our Mothership game, because it was causing some... issues. Indeed unless it's medical (we have an MD!) the DM of that tends to ask me about science stuff, or watches my face to see if he's getting science stuff wrong lol. Most of the time he's "close enough".

As minimalistic as Mothership's default setting is, there's a whole lot that can't be picked at too much or it falls apart pretty quickly. It's very much a "close enough" kind of game.

 

[Bohandas]

So I had a conversation about this once. We were discussing common, expensive material components for spells, ones that have set prices. 100 gp pearls, diamonds and diamond dust, that sort of thing. If there components are consumed by casting (as happens in many versions of D&D), what happens when, you know, the world runs out of them? Even though pearls are grown, there can't be that many of the right price. Or does inflation and local pricing matter? Does Identify require lesser pearls in the desert than it does in a sea town?

Do diamonds automatically replenish themselves, perhaps due to some rift to an elemental plane? Do the Gods do it? Will prices or even components change over time? Are these things bought and sold in a "mage marketplace"?

I just had another thought. What if the largest part of the value comes from some kind of mystical preparation of the gem and not the raw value of the gem itself, and the 'using up' of the gem still leaves you with a gem but one which is no longer suitable for spellcasting and now has only maybe 1%-10% of its former value. These could be recycled over and over again.

 

[aramis erak]

A recent conversation with a friend of mine reminded me of an old issue of Knights of the Dinner Table. In it, the GM (B.A.) was running a science fiction game as a palate-cleanser for the shenanigans of Hackmaster. Long story short, the PC's decided to refuel their starship by dipping into an atmosphere to scoop up some good old Hydrogen, prompting the thread title.

molecular and atomic hydrogen are rare as substances on Earth, Mars, Venus, and most moons not orbiting Jupiter or Saturn.

In chemical compounds, however...

But sometimes, the GM just gets the science wrong! I'm curious to hear about other people's experiences with this sort of thing.

We all get some of the science wrong some of the time.
Our experience of the universe is non-quantum, but at its heart, the universe is quantum

In mine, my friend made the off-hand comment that, in his world, an artifact was used to turn all the oceans into drinkable water. Everywhere.

When I asked him how the environmental catastrophe was averted, he gave me the "shocked Pikachu face".

"What are you talking about? How is this not a good thing?"

That would be a world I'd quit playing in. GM too clueless for me to play "guess the physics" with.

 

[Dannyalcatraz]

Well, the water won't be drinkable for long, what with all the marine life corpses floating in it...

Free soup for everyone!

“Welcome to Bouilla Bay, just off of the Gulf of Ceviche!”