Applying real life logic to DND: How far is too far?

[Silkensword]

There are some interesting things that happen when you try to apply real-life logic to dungeons and dragons, particularly with spells.

Silence is my favourite example.

If truly every little bit of noise is cancelled in an area, that means there is not even molecular movement, because any sort of vibration is sound, instantly freezing the entire area at 0k and killing everything inside and the vicinity.

Where do YOU draw the line? Any fun observations from this line of thinking?


also please don't misconstrue this as me arguing that that should be the effect of the silence spell.

[Kadzar]

Different tables can take it to whatever degrees they like, but I personally feel that you should at least not apply a modern day understanding of physics to D&D.

[kamap]

One I do like is the 5 feet cube from minor illusion could be cast so that is standing on a corner therefor for example could contain the height of a door, you can only make a very slim illusion but it can be higher, instead of 5 feet height it can now have 7.1 feet of height.

Though indeed brining everyday logic into magic is not a good idea, cause logic left the building when magic was introduced.

[kane.84]

If you strike Lightning Bolt in a dungeon room, everyone is pretty much stunned and deaf for a while. If you cast fireball in the same room, it's probably depleted of oxygen. If I'd go this way, it'd spoil the fun for me. I think of this like of action/adventure movie, where I need to sacrifice logic and physics on the altar of fun.

Where is the line? When players are getting frustrated because they can't use their spells or abilities because of the laws of physics. But it's a nice idea to implement some of it, helps to immerse magic into the world.

Once my player cast Fireball in a pretty narrow room, I've added a blast effect that required DC 5 Strength saving throw against going prone. It was easy to beat, only the rogue went prone, so players didn't felt I was being fussy but they felt that the spell made some reasonable effect on the environment.

But I tend not to overuse it, just to add flavor to some encounters and stir events a bit. It's good when a powerfull spell destroys part of the combat ground, like crushes the stone pillar that explodes in shards in the middle of the room, the parts of ceiling dropping down on everyone. These are minor saving throws and little damage caused by the debris so no big deal, but my players memorize such encounters. Especially the mage that sheds destruction feels good if he can witness the power of his own magic and chaos it can bring down.

[Unoriginal]

The line is that what the books say doesn't happen, doesn't happen.

The Silence spell does what it does, nothing more. Dragons can fly. Several fire spells only harm people and not items.

[Kane0]

Disintegrate; conservation of mass/energy? If yes, does it vaporize the target? That is a lot of instant gas, most likely causing an explosion.

Feather fall; does it alter gravity or density? Either one could lead to some unfortunate results...

Any light source; is there any heat/radiation? Can you use them like UV lights to grow plants inside?

Arcane Gate; conservation of momentum?

Enlarge/reduce; the square cube law...

[Asmotherion]

I apply physics that are translated into the existing game mechanics.

If a firebolt deals 1d10, that's it's aproximate magnitude of effect, how hot it is. When it deals 2d10, it means it becomes a more intense flame, burning hoter; Because that's also the approximate damage of the "Heat Metal" spell, the visual effect on a piece of metal that colides with such a firebolt would be to "glow red hot" if multiple of them were used on the same spot on a short time period; it's just that hot. For 4d10, it glows on the first hit.

The Fireball Factor: Back in 3.5, the Fireball Spell had a clause in it's descriptor that said it can melt metals with low melting points, such as lead, gold, copper, silver and bronze. Wile it is not specifically cannon anymore, I take it as cannon.

Here are the mentioned metals melting points:

Lead; 327.5 C
Gold; 1064 C
Copper; 1085 C
Silver; 961,8 C
Bronze; 913 C

This leads us to believe that 8d6 Fire Damage translate into a flame of at least 1085 Celcius, able to melt small amounts of copper (such as a coin); Anything beyond this amount of damage is at least as hot.

Having your magic-physics straight can lead to a world were people won't come up with random physics to abuse. Your World, your Magical Physiscs.

[No brains]

"Every time you try to bring physics into an RPG, God kills a catgirl."

It goes to far when people stop laughing.

[Spectrulus]

In 3.5, I'd try. In 5th, I never bother. As previously stated it's a game for fun and when it devolves into physics questions, it's time to back track.

[kivzirrum]

The line is that what the books say doesn't happen, doesn't happen.

The Silence spell does what it does, nothing more. Dragons can fly. Several fire spells only harm people and not items.

I mean, in a game where many people make house rules, and where fiddling with rules or only using the ones you like are both encouraged, this isn't an entirely accurate assessment. :smalltongue:

[Tiadoppler]

Prestidigitation can clean an object. It makes the dirt disappear.

+

Conservation of energy. If mass is destroyed, energy is released (see: matter-antimatter reaction)

=

Nobody would ever survive casting Prestidigitation to wash their face.

[KorvinStarmast]

Silence is my favourite example. If truly every little bit of noise is cancelled in an area, that means there is not even molecular movement,
Or, it means that the audio signal gain is so low as to be negligible.
You are describing absolute zero.
That isn't what silence creates.
I think of this like of action/adventure movie, where I need to sacrifice logic and physics on the altar of fun. What, Die Hard wasn't a documentary? :smalleek:

[GlenSmash!]

The line is that what the books say doesn't happen, doesn't happen.

The Silence spell does what it does, nothing more. Dragons can fly. Several fire spells only harm people and not items.

This works for me.

On the fly I might not remember what the books say, and make a quick ruling, move on, then look it up after the session and try to remember for the future.

[GlenSmash!]

I mean, in a game where many people make house rules, and where fiddling with rules or only using the ones you like are both encouraged, this isn't an entirely accurate assessment. :smalltongue:

It kinda is though.

Just replace *the rules* with *the rules except in some cases some house rules* and it's still fundamentally the same.

Sill my measure for "should I house rule this?" isn't "is this how it would work in real life" as much as "this is causing a problem for our game"

[UrielAwakened]

In my experience, anything that complains about things being unrealistic in 3.5e or 5e is not okay but anything that complains about things being unrealistic in 4e is fine.

[kivzirrum]

It kinda is though.

Just replace *the rules* with *the rules except in some cases some house rules* and it's still fundamentally the same.

Sill my measure for "should I house rule this?" isn't "is this how it would work in real life" as much as "this is causing a problem for our game"

I mean, personally, I have no concern for realism in regards to physics--it's magic, after all. Except for the sake of humor, as was stated to be the point of the thread. I just don't think it's 100% accurate to say the "line" is slavish adherence to the text of the rulebook. There is no line. Whatever people want to do for their game, power to them, right? :smallsmile:

[Legendairy]

I mirror others in saying “whatever makes it more fun” usually that’s ditching real world physics, other times it’s applying them. So the line can vary from session to session and whatever makes the most fun (if not sense). My players do crazy things fairly often that doesn’t make sense, but sure in the hell is fun! And some of those games are still talked about years later!

[R.Shackleford]

There are some interesting things that happen when you try to apply real-life logic to dungeons and dragons, particularly with spells.

Silence is my favourite example.

If truly every little bit of noise is cancelled in an area, that means there is not even molecular movement, because any sort of vibration is sound, instantly freezing the entire area at 0k and killing everything inside and the vicinity.

Where do YOU draw the line? Any fun observations from this line of thinking?


also please don't misconstrue this as me arguing that that should be the effect of the silence spell.

No limit generally, just sometimes specifically.

I love fantasy and imagination.

LotR is one of the best things to happen to fantasy, but also one of the worse.

[Legendairy]

No limit generally, just sometimes specifically.

I love fantasy and imagination.

LotR is one of the best things to happen to fantasy, but also one of the worse.

I think most of our “limit” is “what makes the players have a good time”. So that “line” moves some much from session to session and game to game.

[Ronnocius]

I feel like applying real life logic to anything besides magic would be a good idea. Magic is magic, no explanation needed in my games.

[Jama7301]

I feel like applying real life logic to anything besides magic would be a good idea. Magic is magic, no explanation needed in my games.

Eeeeh. Then you run into things like like the Guy at the Gym Fallacy for martial characters, unless you're saying PC's are inherently magical.

"Why does his spell do that? That's not how [thing] works in real life!"
"how can you swing your swords 6 times in 6 seconds?"
"..."
"Besides, it's MAAAAAGIIIIC. Have an imagination"
"Then what about my sword"
"Don't be silly, nobody can swing a sword that fast"

Sue me, I've been typing customer support emails all day. I wanted to have some fun.

[PhoenixPhyre]

Eeeeh. Then you run into things like like the Guy at the Gym Fallacy for martial characters, unless you're saying PC's are inherently magical.

"Why does his spell do that? That's not how [thing] works in real life!"
"how can you swing your swords 6 times in 6 seconds?"
"..."
"Besides, it's MAAAAAGIIIIC. Have an imagination"
"Then what about my sword"
"Don't be silly, nobody can swing a sword that fast"

Sue me, I've been typing customer support emails all day. I wanted to have some fun.

I would definitely say that all PCs are magical. A consistent world with magic requires it and more--everyone is magical. How magical depends on the world and the person, but everything is magical because magic is in and through everything.

[Jama7301]

I would definitely say that all PCs are magical. A consistent world with magic requires it and more--everyone is magical. How magical depends on the world and the person, but everything is magical because magic is in and through everything.

Oh, I'm totally with you. That's how I like to construct things. There's a background radiation for magic, and it helps explain the extraordinary.

[Ronnocius]

Eeeeh. Then you run into things like like the Guy at the Gym Fallacy for martial characters, unless you're saying PC's are inherently magical.

"Why does his spell do that? That's not how [thing] works in real life!"
"how can you swing your swords 6 times in 6 seconds?"
"..."
"Besides, it's MAAAAAGIIIIC. Have an imagination"
"Then what about my sword"
"Don't be silly, nobody can swing a sword that fast"

Sue me, I've been typing customer support emails all day. I wanted to have some fun.

It is a good point, but I feel like that in a world with magic you don't need to justify it with real-world science/physics/chemistry/etc. For the swinging a sword 6 times in 6 seconds I prefer the Rule of Cool (is it really that unbelievable?)

Don't worry, no need to sue ;].

[R.Shackleford]

I think most of our “limit” is “what makes the players have a good time”. So that “line” moves some much from session to session and game to game.

Oh yeah, plus it changes for each player.

As long as it fits the campaign, each player can decide their own level of fantasy. Typically we talk before the game about what each wants to do.

[GreyBlack]

The line is where it no longer becomes fun. I have no problem with players solving problems in creative ways and abusing magical physics by applying real life physics if it creates an interesting way to solve an encounter. Room full of goblins? Cast pyrotechnics and lock the door, allowing them to suffocate. Players still solved the problem.

I mean, if it's not fun, then don't do it. That said, if it is fun and it makes sense, then go for it.

[Legendairy]

The line is where it no longer becomes fun. I have no problem with players solving problems in creative ways and abusing magical physics by applying real life physics if it creates an interesting way to solve an encounter. Room full of goblins? Cast pyrotechnics and lock the door, allowing them to suffocate. Players still solved the problem.

I mean, if it's not fun, then don't do it. That said, if it is fun and it makes sense, then go for it.

Pretty much.

[Lunali]

My basic rule for this is magic works the way people expect it to work. If something significantly changes the beliefs of the people in the game world, the effects of magic will change.

[Pex]

When it takes away the fun of playing. Also when you deny something to warriors because it's not realistic but spellcasters can do anything because magic.

[DrowPiratRobrts]

I agree with others that applying physics to magic is too much most of the time (unless you're using it to make a legitimate ruling that's confusing you and your players). Logic on the other hand is entirely necessary to make consistent and fair rulings. The word literally means to reason, and that's exactly what DMs need to do. Can we expect them to rule outside the confines of the world that they live in? I'd argue no since they'll be applying their "real life logical" biases anyway. But I'll play your game...

Let's take sound. You have the scientific definition (vibration that typically propagates audibly across some medium) and the psychological definition (the reception and interpretation of these vibrations). You could argue that the Silence spell inhibits the ability of the medium to actually carry the resonance of those vibrations. Not sure about all of the physics implications, but I'm also pretty sure that it's magic.

[SociopathFriend]

As of my last session apparently too far is trying to carry a pet Basilisk while wearing Winged Boots. DM shut that one right down.

Granted this might be the reverse where the DM firmly stated that regardless of whether I could pull that off with the same amount of equipment (which he would've allowed) he was not going to let me do it with a living creature. So real-life physics was firmly ditched in that scenario.

[Kadesh]

Whenever you get suckered into a Burger beast thread spending 10 pages on what happens according to the rules and disagreeing with the rules.

[lxion]

The line is where it no longer becomes fun. I have no problem with players solving problems in creative ways and abusing magical physics by applying real life physics if it creates an interesting way to solve an encounter.

Yeah, that's my opinion on this as well. If they think of an interesting way to use their spells/items out of context, I am usually curious to see how this would turn out. Throwing the Instant Fortress out and landing it upon a group of enemies or using Heat metal to light arrow tips of friends and stuff. Not the most creative, but still fun.

[Contrast]

There are some interesting things that happen when you try to apply real-life logic to dungeons and dragons,

I mean its a living breathing world so some things just kinda have to follow our logic as you can't have rules for everything.


particularly with spells.

You've gone too far. Spells are literally magic. They do not follow any comparative logic or rules we have in this universe. Plus they're designed for a game that is at least hopefully somewhat enjoyable. Fireball sets fire to things...unless you're wearing or carrying them for some reason.

The game has a DM for a reason and with D&D part of that reason is to adjudicate what makes sense in relation to how spells work. Trying to rules lawyer spells is not what (most) games are about and therefore (most) GMs do not look favourably upon it (or they'll let it fly once but tell you not to get silly with it).

[dmteeter]

Just don't do it at all. Treat your fantasy world like a fantasy world.

[Millstone85]

That's when magobabble comes in. It's magic, I ain't gotta explain it... more than is, in fact, pretty fun.

Disintegrate should cause an explosion? Clearly, the energy is dissipated through the planes.

[Strangways]

There are some interesting things that happen when you try to apply real-life logic to dungeons and dragons, particularly with spells.

Silence is my favourite example.

If truly every little bit of noise is cancelled in an area, that means there is not even molecular movement, because any sort of vibration is sound, instantly freezing the entire area at 0k and killing everything inside and the vicinity.

Where do YOU draw the line? Any fun observations from this line of thinking?


also please don't misconstrue this as me arguing that that should be the effect of the silence spell.

How do you know that a silence spell doesn't impose silence despite the continuation of molecular motion in the area? The whole point of magic is that it can break the normal, physical laws of the universe, isn't it?

[opticalshadow]

I think there are just bigger problems outside the rules. The world doesnt make sense.

Why are their starving people with clerics and good wizards who can just make food, they can just make homes, they can create pretty much anything. why woudlnt every army just have cloudkills float into cities and kill everyone, why are so many of the buildings and systems and way of life so similar to earth middle agesish when they have magic that can bend reality and our idea of physics at cantrip levels. Why are their sick people when we have cure spells. Why dont druids all have leagues of awakend plants tending to gardens that grow a years worth of food weekly, why are none of the kings ever powerful enough to tell the archmage his place?

everything about dnd society doesnt make sense once we just apply logic to its own rules, let alone apply our rules to it logic.

[Contrast]

I think there are just bigger problems outside the rules. The world doesnt make sense.

Why are their starving people with clerics and good wizards who can just make food, they can just make homes, they can create pretty much anything. why woudlnt every army just have cloudkills float into cities and kill everyone, why are so many of the buildings and systems and way of life so similar to earth middle agesish when they have magic that can bend reality and our idea of physics at cantrip levels. Why are their sick people when we have cure spells. Why dont druids all have leagues of awakend plants tending to gardens that grow a years worth of food weekly, why are none of the kings ever powerful enough to tell the archmage his place?

everything about dnd society doesnt make sense once we just apply logic to its own rules, let alone apply our rules to it logic.

I would point out that most of the comments you've made there are equally true of the real world yet we still have hunger and wars and homeless people and people sick with easily preventable diseases.

Plus the old 'PCs are special' thing whereby just because PCs have a lot of magic users and advance relatively quickly in level does not mean thats true for the rest of the population.

[Greywander]

D&D physics might not be the same as real life physics. Oh, sure, the end result looks similar enough, but that doesn't mean that it works the same behind the scenes. You're probably okay in applying Newtonian physics, but I wouldn't even try to bring up Relativity or Quantum Mechanics.

Another thing to consider is that lots of things, more than just spells, are magical, and this magic actually is part of the "physics" of the world. Presumably, there are rules as to how it works, but you probably don't know them, unless maybe you're a wizard who studies them. But even without bringing up spells, there are already plenty of situations where our understanding of physics simply doesn't apply because magic.

In reality, though, the rules are whatever the DM says they are. There's no secret chapter in the DMG detailing the physics of D&D and how magic interacts with physics. As many have said, you've gone too far when you stop having fun. I'd also remind you that in trying to assert that things would work a certain way, you might just be creating the rules on which that world operates; this can be great fun until the DM turns it against you, which they totally should if you're repeatedly using the same cheap tactics. After all, turnabout is fair play. It's also much more efficient for the DM to let the players invent a counter to a problematic strategy instead of trying to come up with one themselves.

[opticalshadow]

I would point out that most of the comments you've made there are equally true of the real world yet we still have hunger and wars and homeless people and people sick with easily preventable diseases.

Plus the old 'PCs are special' thing whereby just because PCs have a lot of magic users and advance relatively quickly in level does not mean thats true for the rest of the population.

While true, in dnd one spell caster per city could wipe these problems out before lunch, in the real world it would be more complicated then a days worth the spell casting and it would take effort of alot of people and resources. In dnd its literally just a matter of a handful of even less then medicore casters to deal with it. it realyl wouldnt cost anything, it wouldnt require logistics each town could just have one person to do it to be easy, i mean, its magic.

[PhoenixPhyre]

While true, in dnd one spell caster per city could wipe these problems out before lunch, in the real world it would be more complicated then a days worth the spell casting and it would take effort of alot of people and resources. In dnd its literally just a matter of a handful of even less then medicore casters to deal with it. it realyl wouldnt cost anything, it wouldnt require logistics each town could just have one person to do it to be easy, i mean, its magic.

Create food and drink is a 3rd level spell. That means 5th level caster to cast 2x/day. It's also cleric only, and not all clerics will choose it or even know it exists (depending on the god in question). 2 castings feeds 20 people. So for a population of 1000, you need 50 clerics who can cast this spell.

In my setting, that would imply that 5550 of the 1000 (at least) are clerics-- 50 that can cast level 3 spells, 500 that top out at level 2 spells, and 5000 that can cast only cantrips and 1st level spells.

Scaling is a problem.

[JackPhoenix]

Problems that show up every time this sort of thread pop up are that magic is part of the laws of physics in D&D, and those laws are different than what we have in real life thanks to that, and that most people don't know as much about real physics as they think they do.


Silence is my favourite example.

If truly every little bit of noise is cancelled in an area, that means there is not even molecular movement, because any sort of vibration is sound, instantly freezing the entire area at 0k and killing everything inside and the vicinity.

Active noise cancelation is a thing that exist in real life. Silence is merely a version that works much better than what we can achieve... as if it was some kind of magic. You also (as noted by KorvinStarmast) don't have to cancel all sound, merely what would be audible to creatures in the area of effect... and the effect is selective, as a Rakshasa inside the area would be able to hear normally. As written, sound can't exit the area, but can enter it normally, it's just that creatures inside are deaf, which supports the "very advanced version of existing tech" explanation.


Snip

That's not how it works, and the clause was stupid. Fireball is an instant effect, the heat exists only for a moment. If you can transfer enough energy to melt any substantial amount of gold in such short time, you would also turn the air into plasma and vaporize anything organic in the area. It's not just a matter of temperature.


Disintegrate; conservation of mass/energy? If yes, does it vaporize the target? That is a lot of instant gas, most likely causing an explosion.

No, it turns it into a pile of dust. There are no details about that pile of dust, but it's not unreasonable to assume it's got the mass of the original creature, minus some gas.


Feather fall; does it alter gravity or density? Either one could lead to some unfortunate results...

Perhaps it simply provides force to provide limited lift against gravity. No need to mess with either.


Any light source; is there any heat/radiation? Can you use them like UV lights to grow plants inside?

By definition, there's radiation, as that's what light is. There isn't any heat unless the spell specifically says so. And if the spell counts as sunlight, it's noted in the description.


Enlarge/reduce; the square cube law...

Either doesn't apply the same way, as there are natural giant creatures, or the structural integrity of the enlarged creature gets strengthened by magic.


I think there are just bigger problems outside the rules. The world doesnt make sense.

Why are their starving people with clerics and good wizards who can just make food, they can just make homes, they can create pretty much anything. why woudlnt every army just have cloudkills float into cities and kill everyone, why are so many of the buildings and systems and way of life so similar to earth middle agesish when they have magic that can bend reality and our idea of physics at cantrip levels. Why are their sick people when we have cure spells. Why dont druids all have leagues of awakend plants tending to gardens that grow a years worth of food weekly, why are none of the kings ever powerful enough to tell the archmage his place?

everything about dnd society doesnt make sense once we just apply logic to its own rules, let alone apply our rules to it logic.

Per default assumptions, spellcasters are rare. 95% or so people are commoners. High level spellcasters are even rarer, and have better things to do than to attend to need of some peasants. Wizards can't make food and they need to be level 9 to make a stone wall (and you need more than one to make a home), Clerics needs to be 5th level to feed 20 people, and you can't exactly train either... wizards need rare talent, and clerics are directly chosen by their god. Cloudkill needs level 9 caster, and gets stopped by the first wall or ditch in the way. Cure spells won't help with diseases, they "restore HP", whatever that means, as HP aren't just direct physical damage, and can't even restore lost limbs or eyes. There are spells for that, but those again requires higher level casters. Druids don't do that sort of thing, because awakened plants aren't farmers, there's no magic that helps you grow food that fast (though you can improve crop yield) and druids aren't exactly fans of civilization in the first place, so why would they support more of it? As for the kings and archmages, that's not exactly true... sometimes the rulers *are* the archmages, often the archmage works for the kings.

And of course, there are settings that do make more sense than Forgotten Realms too.

[Darth Ultron]

Too far is when things stop becoming fun.

Though also note ''logic" is separate and different then ''science".

The problem I see a lot of players do is they take their Basic High School Science, glance at the D&D rules and then look for exploits, loop holes and ways to break the game.

And everyone that does this just ignores that in reality science can get weird, and not everything in reality is perfect and fits into ''rules".

A great example is just water. Basic Science tells you that if you get water cold, down to zero(or 32), it will turn into ice. And that is true...and not true. Take a look around Earth and you will find oceans of water at both poles of the planet, where it is very cold. And yet, there is liquid water there..woah, must be some weird magic right? How can water always become ice when it gets cold....and then always not become ice when it gets cold.

And reality is FULL of stuff like this. And, of course, the explanation is simple enough.

But this is where you get the big problem with fiction magic. People get stuck on the rule like ''all water MUST be turned into ice when it gets cold absurdity forever!" and it's impossible for them to accept the thing like ''well, sure that is true some of the time....but" type things...the things you find in everyday science. Yet people can't seem to accept such things could be true in fantasy science.

[furby076]

There are some interesting things that happen when you try to apply real-life logic to dungeons and dragons, particularly with spells.

Silence is my favourite example.

If truly every little bit of noise is cancelled in an area, that means there is not even molecular movement, because any sort of vibration is sound, instantly freezing the entire area at 0k and killing everything inside and the vicinity.

Where do YOU draw the line? Any fun observations from this line of thinking?


also please don't misconstrue this as me arguing that that should be the effect of the silence spell.

Silence doesn't allow sound to travel. You can still scream, it just doesn't go anywhere. Also, it's about reading too much into things. Applying real-life logic to a game that includes magic, dragons, undead, aberrations, etc.... I guess it could be fun to find out an effect and extrapolating. Like, its theoretically possibly someone fall 130 feet and live (13d10, vs fighter who has 18 con and get all 1's).

[Sigreid]

Or, it means that the audio signal gain is so low as to be negligible.
You are describing absolute zero.
That isn't what silence creates. What, Die Hard wasn't a documentary? :smalleek:

If you want to explain silence with science, the spell could also automatically generate a sound wave of equal amplitude 180 degrees out of phase, cancelling the sound. This works.

[Laserlight]

Apply real life logic when you're trying to figure out how the players interact with the environment in ways not mentioned in the rules. For example, you have Water Breathing but you've teleported to a spot 2000ft deep in the ocean. Are you crushed? Do you get nitrogen narcosis? The bends? Are your lungs full of water, or is there some interface at your mouth that filter oxygen out of the water for you?

Then realize that you're in a universe where pi = 4.

[Millface]

physics should only be applied to magic when the spell specifies that it should, because it's magic. In a hard magic system, it doesn't have to make sense. The effects work more or less exactly how they're described because they just do.

Outside of magic, on the other hand, go nuts.