D&D 5E DM's: How Do You Justify NPC's Having Magic/Abilities That Don't Exist in the PHB?

[Lanefan]

For those who follow this idea.
Please explain in game what happen five minutes ago. We were using the PHB just last Saturday, but Wotc just dropped a new book on Tuesday.
Why does your wizard have the new "Silver Bullet" cantrip in his head?
Why does Oofta looks more like an orc?
Why is my gnome now a robot and good at technology/
Because in game just five minutes ago, orcs were monsters now they are pc races. The cantrip did not exist. And neither did autognomes or artificers.
What in game Magic is physics allows this to happen every time WoTC drops a new book?

None. If the book didn't exist at the start of the campaign it by default doesn't enter into that campaign. You're still using the book as it was last Saturday and will be for the remainder of this campaign.

That said, if I or a player see something cool in the new book that thing might find a way into the ongoing campaign once an appropriate in-fiction rationale can be made for it.

Back in 1e when Unearthed Arcana came out, we picked and chose what parts of it to include. In-fiction, there was an explosion of new spells across the world's MU guilds as books of previously-unknown or forgotten spells came to light; and from acorss the sea came these funny Cavalier things we'd never heard of.

But never was there any assumption that the book would be adopted wholesale, and it never was. Same holds true here

 

[TwoSix]

If your world's gravity is only half that of Earth, for example, jumping becomes much easier and missile ranges go up by a huge amount; carrying capacities likewise unless strength is adusted to suit. It also means the atmosphere will work differently, and probably be either considerably thinner (like on Mars) or considerably deeper above the surface than we're used to; either of which will affect the colour of the daytime sky and the brightness/colour of the sun(s). Weather will also be vastly different than what we're used to; and is gravity lower because the world is smaller than Earth (which will affect your mapping) or because it's hollow (which will play merry hell with your geology as the planet doesn't have a molten core)? Etc., etc.

"If you're wondering how he eats and breathes
And other science facts
LA LA LA
Then repeat to yourself, "It's just a show,
I should really just relax"

 

[Maxperson]

For those who follow this idea.
Please explain in game what happen five minutes ago. We were using the PHB just last Saturday, but Wotc just dropped a new book on Tuesday.
Why does your wizard have the new "Silver Bullet" cantrip in his head?

Because that cantrip has been around for 10,000 years and has such a crick in the neck! It just wasn't revealed to you until Tuesday.

Why does Oofta looks more like an orc?

That makes no sense.

Why is my gnome now a robot and good at technology/

Your gnome isn't, because you didn't choose autognome or artificer when you made him.

Because in game just five minutes ago, orcs were monsters now they are pc races.

Which doesn't alter the look of orcs. Poor @Oofta.

The cantrip did not exist.

It did.

And neither did autognomes or artificers.

Just like the cantrip, they did in fact exist prior to the book. I'm not sure where you get this idea that things don't exist in the world until after the books are released. The books just detail more of the world that already exists.

 

[Blue]

Because DMs didn't shortcut where they could have.

Sorry, the idea "they didn't use the 'right' method" is incompatible with "the 'right' method isn't usable unless DMs are shortcutting and not actually using the 'right' method".

It doesn't matter how the NPC is built or prepped or dreamed up as long as the end result could be achieved by a player rolling up the character at that level.

This needs some support more than just saying it, it is not self evident. PCs and NPCs have no need to be the same.

Or a relaxation of bounded accuracy, which - in moderation - might be a worthwhile idea.

So is bounded accuracy also "the wrong choice the devs made", or just inconvient because it's in the way of your other goal so you can toss it?

 

[Shadowdweller00]

There really isn't any need to overthink this. Most enemies get "screen time" for maybe a battle, at least in the foreground, whereas PCs last the whole campaign. So there are whole hosts of abilities (like low-level teleportation or damage bonuses that won't stack with other stuff in NPC hands) that aren't unbalanced for enemies but are for the PCs. But it's also the DM's job to adjudicate the world. When PCs want to try to use, play around with, experiment with, or research magical effects in the world it's better on multiple levels to have answers for their efforts rather than writing it off as "just magic". And it's a lot more fun to at least occasionally include usuable results and new options.

Sometimes even published adventures include various effects that it should be possible to interact with. For example, the water-faction in Princes of the Apocalypse carry these shark-toothed swords that deal extra damage. So what happens when the PCs pick one up and try to use it? Might not be balanced if they have the extra damage at the point they find the swords. It's pretty easy to come up with a reason as to WHY they can't use them, say "the blades seem to be stabilized by the will of some sort of outside, water-based spirit"; and then have them dry out and crumble after maybe a round or two once the wielder is dead. (Still letting the PCs use the blades briefly). Instead of just telling the PCs that they can't use the swords by fiat. And maybe, just maybe, one of your PCs eventually signs a pact later on with some sort of water creature (such as gaining levels in the Fathomless Warlock subclass) down the road. Maybe you'd let that PC keep and maintain one of those swords since now they have the support of a magical water spirit.

 

[Micah Sweet]

"If you're wondering how he eats and breathes
And other science facts
LA LA LA
Then repeat to yourself, "It's just a show,
I should really just relax"

The MST3K mantra doesn't work for everybody.

 

[pemerton]

If your world's gravity is only half that of Earth, for example, jumping becomes much easier and missile ranges go up by a huge amount

I think this is missing my point and @TwoSix's point.

Gygax treats jumping as normal. But he also suggests, as a credible element of a D&D campaign, that a high level fighter can mount a pegasus and fly to the moon: "suppose that you decide that there is a breathable atmosphere which extends from the earth to the moon, and that . . . one beyond the normal limits of earth's atmosphere, gravity and resistance are such that speed increases dramatically, and the whole journey will take but a few days" (AD&D DMG p 58).

There's no way I know of in which that can be presented as genuinely coherent: no flying creature can travel 100,000 km per day, no matter how little the gravity; but if the moon is much closer than - given its size in the sky is as normal - it must be much smaller - but then it would have no significant gravitational pull of its own - and that's before we even consider what holds the atmosphere in place - etc.

There's no "world as physics" account of this to be given, any more than that can be done for REH or HPL-ish creatures who travel through space on magical wings (as in The Tower of the Elephant). These aren't quasi-scientific explanations; they are all just tropes. Yet Gygax was able to run very successful RPG campaigns; and so have many more of us who have relied on tropes and genre as the underpinnings of our settings.

 

[Incenjucar]

Flying to the moon on a pegasus works just fine if you throw the 2E Ethereal or portals into the mix. The Planescape Ethereal Plane book has rules about exceptional movement speed AND moons that are somehow there but also real (Krynn's moons, in fact).

You can also design a setting that has explicit mythical properties that work alongside normal physics. "Moving toward a celestial body with intention for 2d4 days will allow the traveler access to mythic movement, treat as an ethereal vortex except it ends in a demiplane containing a reflection of the celestial body"

 

[Lanefan]

Sorry, the idea "they didn't use the 'right' method" is incompatible with "the 'right' method isn't usable unless DMs are shortcutting and not actually using the 'right' method".

Er...I'm not talking about right or wrong method. I'm talking about the end result being achievable using the standard method regardless of what method (if any!) was actually used to get there.

If the possible end result for a player is between 3 and 18 and your end result falls within that range, I don't give a frig about how you-as-DM got it there. But if the possible end result for a player is 3-18 and your NPC shows up with a 25, or a -1, we have a problem.

This needs some support more than just saying it, it is not self evident. PCs and NPCs have no need to be the same.

For in-the-moment gameplay, no they don't...until and unless a player quite rightly asks "Why can't I do what that NPC can do?" or even "Why can't that NPC do what I can?".

I'm looking at it from a broader standpoint, however: that of consistency within the setting. People in the setting don't have "PC" tags on them just because they've got a player attached; and for the sake of setting integrity should in all ways be indistinguishable from NPCs of the same species. Put another way, unless the PCs are somehow alien to the setting, PCs and NPCs should be seamlessly interchangeable without having to touch their mechanics. From this standpoint, it goes without saying that they are the same.

So is bounded accuracy also "the wrong choice the devs made", or just inconvient because it's in the way of your other goal so you can toss it?

Neither. It's a good idea they perhaps took a bit too far; but I'm not sold on finely-tuned game math in any case (WotC have overdone the fine-tuning all the way along) and am happier with a bit more randomness.

Sort of a toned down version of what they did with advantage-disadvantage: they hit on a good idea and then just used it way too much.

 

[Lanefan]

I think this is missing my point and @TwoSix's point.

Gygax treats jumping as normal. But he also suggests, as a credible element of a D&D campaign, that a high level fighter can mount a pegasus and fly to the moon: "suppose that you decide that there is a breathable atmosphere which extends from the earth to the moon, and that . . . one beyond the normal limits of earth's atmosphere, gravity and resistance are such that speed increases dramatically, and the whole journey will take but a few days" (AD&D DMG p 58).

If I ever read that (and I probably did, sometime) I immediately forgot it, so thanks for the page reference.

There's no way I know of in which that can be presented as genuinely coherent: no flying creature can travel 100,000 km per day, no matter how little the gravity; but if the moon is much closer than - given its size in the sky is as normal - it must be much smaller - but then it would have no significant gravitational pull of its own - and that's before we even consider what holds the atmosphere in place - etc.

Which is why in the sort of setting I prefer, such a thing just wouldn't work. If you want to get to the moon (and have means of surviving once there!) you can find a spaceship, or try planeshift*, or a wish.

* - in my system planeshift allows world-to-world travel within the PM as well as travel to other planes, otherwise world-to-world can't happen - teleport sure don't work for it!

There's no "world as physics" account of this to be given, any more than that can be done for REH or HPL-ish creatures who travel through space on magical wings (as in The Tower of the Elephant). These aren't quasi-scientific explanations; they are all just tropes. Yet Gygax was able to run very successful RPG campaigns; and so have many more of us who have relied on tropes and genre as the underpinnings of our settings.

Fortunately for all, perhaps, while I throw a few HPL-like elements into my setting (usually monsters and-or quasi-deities) I don't use anything of his for actual worldbuilding. And yes, tropes like that can be fun in stories where there's no need for anything to be consistent outside the immediate story being told; but for an RPG setting that's going to be widely travelled and (one hopes) host to many different stories, this approach falls apart in a hurry.