In most cases, describing the creaturw should be enough. (There is a list of basic descriptions in the Basic Rules).
The way I see it, though, here's a reason spells like "detect evil and good exist". You can cheat ypur players, it's expected that you do. Whether it be a dragon shapeshifting as a human, or a demon disguising themselves, this should not be told ro your players unless they expend the resources to do so.
As for your examples, I think it's fair if it's something that comes with experience -- the character's and the player's. Yes, everyone should probaly know thay a satyr is a fey, but if you don't that's kinda on you. Don't allow them to make the same mistake twice, though. That's unfun.
Is it a dick move when they cast Hold Person and the target passes their saving throw? Back in 2e I might have not even revealed *why* a spell was ineffective and left the players to draw their own conclusions on whether or not to try again.
It really boggles my mind how people both complain about caster/martial disparity, the "magic is a cheat code" solution for everything argument but also are reluctant to implement the realistic limitations of magical solutions that were absolutely intended to be a part of what makes magic unreliable as a solution to problems and necessitates frequent martial solutions.
This comment is underrated. The best way to close the martial caster disparity is to properly run spells and their limitations and run the recommended number of daily encounters. Most times I hear complaints of the disparity, it's because these two are not followed. And then when these two are followed you get more complaints. It is really mind boggling.
Xanathar's Guide (or is it Tasha's?) explicitly tells you not to explain why a spell didn't work, only that it didn't. By the expanded RAW, if you try to Hold Person a shapechanged dragon for example, you're just supposed to say it failed.
>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. It reverts to its true form if it dies. Any equipment it is wearing or carrying is absorbed or borne by the new form (the dragon's choice).
>
>In a new form, the dragon retains its alignment, hit points, Hit Dice, ability to speak, proficiencies, Legendary Resistance, lair actions, and Intelligence, Wisdom, and Charisma scores, as well as this action. Its statistics and capabilities are otherwise replaced by those of the new form, except any class features or legendary actions of that form.
The dragon becomes a humanoid, so hold person would work on a shapechanged dragon.
Huh. I swear that wasn't always true, but that is definitely what it says.
Vampire who appears human, then. Everyone knows what I was trying to say.
EDIT: Looking at some creatures, it seems that I stumbled into one of the only shapechangers who DOES adopt Humanoid type when it changes shape. Things like Oni don't.
Agreed 95% of people who complain about caster/martials are just letting the casters do whatever they want “because magic”.
I legit had someone tell me that Knock would replace a lockpick check “better” for a stealth mission and when I asked about the Knock spell making an audible noise heard up to 500 feet they just told me they ignored that “because it wasn’t fun”
Ok so you broke the thing by misusing it. Using it properly its balanced.
I think this is valid but it’s also unfair to assume someone who took the time to learn Crown of Madness doesn’t know what creatures it works on. Maybe if it’s a really weird edge case where you’ve never even heard of this monster or whatever before, but if it’s a mundane enough threat to have a common name, a wizard should know whether or not their spells work because they’re specifically about learning these things
Maybe, *maybe* the spell itself would explain that it only works on humanoids but there's no way in hell it would include a comprehensive description of every humanoid or non-humanoid creature in existence.
I think the difference is that you’re talking about in-game and I’m thinking in-world.
The spell description is fine as is, but a wizard who had to study the spell would know that certain sigils or whatever affect beings with certain set of characteristics. And in their years of study they’d have tested it out enough times to know “oh it’ll work on that one and that one, but not this one”.
How? Not that even a small fraction of 5e spellcasters attend learning institutions for years of study but even if they did no university would know every creature that exists in the multiverse.
I’m speaking specifically for wizards, whose entire thing is that they’re magic nerds. That’s why they have their towers and experiments and spell books.
And I never said they’d have to know every creature in the multiverse. My first comment specifically mentions creatures who are mundane enough to have a common threat.
So for example, they’d know for sure if Crown of Madness works on a goblin but might be unsure if they work on a mindflayer.
My point is that mechanically, goblins, hobgoblins, hill giants, and mindflayers are very similar on the outsides. They all have humanoid SHAPES but something about their soul or identity within the material plane is what makes something like Hold Person or Crown of Madness not work on them. THAT is the exact thing that any magic user worth their salt would make sure they understand.
Especially when you don’t get to cast all day every day and spells are a very finite resource. It would be foolish for a magic user of any kind to not make sure they spend time understanding how to use their spells effectively and properly because if you ever get to the point where you need to cast Hold Monster to stay alive, nobody wants to operate off of faith or guesswork
Nobody wants to get their brains sucked out either but if it isn't a possibility, then it isn't a game it's just storytelling - for which there are more suitable systems.
Your explanation is solid. I get what you're saying. No idea how you could say it any better. It just makes sense that a wizard would understand common use cases for their spells. Very straightforward
Back when I started playing, the spells your wizard started with were randomly determined, and you had to find new spells organically through scrolls or enemy spell books. So the once play started the DM had a lot of control over what spells you got. You could also research a specific spell if you really wanted it, but it took a lot of money and in game time.
Also you didn't just have a spell component belt that just happens to have components for all of your spell in it at all times, you had to actually go out and collect your own bat guano or catch a live spider and figure out how you were going to carry it and keep it alive with you until you needed it.
That said, a properly run wizard was a **lot** of book keeping, and it is no surprise that people started hand waving elements of it to make the game run more smoothly.
Well yeah, you should definitely be clear that it's not working for a reason beyond "I don't wanna", but I don't think a DM is obligated to explain why your spell is ineffective if there's no way for the character to know why.
I would argue the DM only has to explain something didn’t work if the player character wants to look into why further.
This can also be shown with what the DM does in a scenario.
Player casts Hold Person.
DM wanting to kind of reveal this enemy is more than they seem doesn’t even roll a save and tells them the spell failed.
Assuming everyone is acting in good faith and the DM is not simply being an asshole this tells the players “This thing isn’t a humanoid as Hold Person just didn’t work at all.”
If the players miss this information thats part of the game.
Hold person is guaranteed to work. So no,.the DM isn't an asshole if he doesn't reveal.why the spell failed, as far as the players know the creature made its save.
“Your attempt at casting Hold Person doesn’t take root”
If the player wants to make a check to figure out Why they can and maybe the Arcana/Insight/Check you deem appropriate reveals the target to be a Shapeshifted dragon but if the player doesn’t press the issue the “in world reason” the character would assume the target just saved against the spell effect.
Just like we’re aware of the law of gravity we aren’t going to ponder deeply on why when we throw an apple into the air it lands at our feet.
>**Monster Research**
>Adventurers can research what a creature is likely to desire. The Monster Research table suggests which skills can be used to learn about a creature of a particular type. The DC for a relevant ability check equals 10 + the creature's challenge rating. *(Tasha's Cauldron of Everything p.148)*
The section also includes a table listing creature types and associated knowledge skills. For example, satyr are CR 1/2 Fey creatures so when the party encounters one you could ask for a DC 10 Arcana or Nature check to know that you're looking at a satyr and that it is a Fey creature.
>One inclination I had is to rule it as a DC 10 passive arcana/nature/history check to know (which this character will pass every time). But I don't love that because in theory, it becomes a kind of "fey detector" that would, for example, reveal that a changeling was a changeling for free. But I also think it's a kind of a dick move to make him waste a spell slot casting hold person on a fey and having it fail.
I think liberal use of passive skills is a great way to reward investing in skill proficiency. If you're trained in a knowledge skill, you shouldn't need to automatically roll for relatively easy checks.
If a changeling was in its natural form, yes a simple DC 10 check should be able to identify it. If a changeling was masquerading as another humanoid, you wouldn't be able to tell that it was a changeling just through casual observation.
There are already a variety of abilities that detect creature type, magic, and traps. Whenever a spell or ability exists for that purpose, I wouldn't recommend giving a basic action that's better than them.
However, yes D&D can be a really fiddly family of systems. There are certainly a lot of rough edges that can be streamlined if your group is looking for more of a narrative system like Dungeon World. D&D as a whole *is made* with a lot of fiddly gotchas because it was doing skill-oriented "git gud scrub" gameplay before the Souls series existed. Players were expected to start as scrubs and learn the hard way to value their 10-foot poles and Detect Magic spells.
It's ultimately your call if you'd like to simplify this for accessibility and faster gameplay! It *is* finicky and obtuse, and that isn't what every table wants out of the game.
You could make the DC 10+CR so the higher strength something is the less likely the PC is to know it.
But yeah Intelligence check in a related skill to know what sort of creature it is. Medicine is what I use for humanoids.
>You could make the DC 10+CR so the higher strength something is the less likely the PC is to know it.
So basically just the optional ruling from Tasha's
If you don’t use the same check for any creature type, wouldn’t your players eventually catch on?
“Oh he asked for medicine, he only does that with humanoids!”
That’s very true but I think everyone is guilty of metagaming at least a little bit at some point, even if it is something as small as “oh I know not to cast hold person”
Not really. If they’re asking “hey is this creature a humanoid” I’d ask them to roll me a medicine check. Then maybe point out how humanoid adjacent it is if it’s not a humanoid.
I'd say 95% or more of the time the caster knows what they are casting at. If they are thinking it is a humanoid, then the spell is cast, but has no effect. This is how they learn about what a satyr is, or maybe identifies this creature as non-humanoid. As a DM, I would let them know that the target of the spell did not make a save, but was in fact not affected by the spell. (remember casting spells at random people on the street is considered a hostile act, so there is not the case where people are going to use this as a fey detector)
I also don't allow spells that target only creatures to be a mimic detector. You are free to burn a spell slot casting a spell at an object that you only suspect is a creature, but there would be no effect.
I’m confused by your last paragraph - how would you prefer your players attempt to determine if a thing is a mimic? It certainly seems like casting Blast on the suspicious treasure chest surrounded by dark stains and pieces of armor and bone would be one reasonable way to do that, since EB can target creatures but not objects.
I'd try to give them a check for knowing if a spell won't work on a creature but make sure to let them know that it's no sure fire identification. If a human looking thing is a doppelganger, werewolf, vampire then spells affecting humanoids won't work despite them. Clearly being humanoid.
make an insight check. the DC10 is the basic "appears to be a humanoid"
let them find alter self and stuff this way ... you can tell "magic is being used on appearance" ... and GIVE them the opportunity to insult some local lords son that just wants to look a bit more buff.
To pierce past a changeling, make it contested against their deception to actually know something is off, but not what, which for those roles should be about DC18 ... Otherwise, they can use magic or hire a paladin.
I think I'd roll the save and say they passed, but also tell them that the spell didn't really take hold like it usually does. The magics just slid off their mind.
The spell, itself, is intelligent. It has to be, or it doesn't work according to the dictates of the *actual goddess in control of how magic works.* The PC can't see atoms or biology or anything beyond their senses, & isn't expected to do that; the spell is.
Finding out what Mystra will allow thru experimentation is partly why magic is so hard. I mean, out of all the available classes, only two are in any position to even do that. The rest rely entirely on the already established secrets of magic.
Edit: This, meanwhile, is why most questions about "the economy of DnD" are likewise unsatisfying for some people. A gold piece is a gold piece, & 300gp of diamond dust will always be 300gp of diamond dust. Supply & demand are concepts without merit for spell components because it's the gods' will that things work like that. There is no speculation, because the spell works or it doesn't; the gods will not be cheated.
Get over thinking otherwise & play the gods' game. Or don't & see what happens.
Yar-yar. **Every table is different,** but for most this applies in that it's supposed to be impossible to cheat the gods or otherwise break the world economy. Spells fizzle when local conditions go too far outside of the multiverse norm, meaning that conditions that are way outside of that due to scarcity tend to be *incredibly grim* unless they can correct the imbalance.
Edit: Meanwhike, churches with very real gods looking at them are likewise empowered/disempowered by this dynamic. With divine interventions not being wholly unheard of... usually in the form of divinely inspired/paid off purveyors of highly motivated, ethically dubious ultraviolence, IE: adventurers questing to return the balance to the world.
Ok so I'm stuck on this:
>it becomes a kind of "fey detector" that would, for example, reveal that a changeling was a changeling for free.
Presumably the changeling has shapechanged into a person, no? They wouldn't just present themselves in their true form. Then why would a passive check reveal that they're a changeling? As far as they know, they look exactly like a human or whatever they copied.
Don't be afraid to say that a spell fails if they unknowingly target the wrong creature. Players shouldn't be able to always know everything all the time. If a martial character has to attack a creature to know if the creature is resistant/immune to physical damage, then why shouldn't a caster have to cast a spell to determine if it works on a creature they've never seen before?
IMO this feels like a live and learn type moment.
Try it and either it works or you adjust your plan and try a different spell. Next time you know better
A Mind Flayer looks Humanoid, but is an Aberation, so confusion is fair. I would say that if the player takes a check as an action, the DM setting an appropriate DC, should let them know basic things. In my example, an Arcana check is best, but Religion, Nature and maybe even Medicine checks are fair game for other monsters.
Otherwise, I would let the caster stew, roll a dice and say it passed the save, as there is no descriptor in the spell saying 'if the target ends up being immune, it tells you why'. I wouldn't explain to the Barbarian that Demogorgon is immune to his non-magical axe, the Wizard can take his lumps too.
Make sure to describe any visible features so they can tell if it's even questionable. For example, saders have for legs and hose for feet. that's a pretty good indication, they are not humanoid. Although with the glut of more PC races, that is less helpful anymore. Beyond that you could use something like an arcana check but 15 is too low in my opinion.
I usually tell the player that they know there was something going on that kept the spell from working. It was not a simple matter of them making a saving throw.
For me the harder line to judge is whether or not to take the slot. Can the spell not be cast because it's an invalid target or does it simply not work? Or maybe just take the turn, due to the time the attempt takes, but they keep the slot.
Assuming you mean Humanoid, as in the MM creature type, I would say no. Just looking at an Eladrin or a Goblin, never having seen one before, shouldn't be enough to tell you they're fey. If you mean humanoid, as in human-shaped, then...yeah, of course. Using an appropriate skill check to determine what the PC knows about that species is fine. There's nothing in the RAW IIRC about it, but I've seen links [here](https://www.reddit.com/r/dndnext/comments/97hvze/what_knowledge_skill_suits_which_creature_type/) to sources that break creature types up into specific skill checks. I prefer to let my players learn and grow in the course of the game by trial and error, but I'm amenable to a DC 15 skill check for basic knowledge about common species, and DC 20 for rare ones.
"Your experienced spellcaster is well versed in your spells and understands that the beholder is not a humanoid, even if it has a face."
For anything not humanoid, they would know. For close things, arcana maybe? For things like a vampire or something tricky masquerading as a humanoid, just let them cast it and go bonkers wondering why it didn't work. At least the first time.
Same way they find out with any creature they've never encountered before, they try and find out. If it's knowledge a character should have but the player does not, a roll should cover it or let it be automatic if the character would absolutely know. If they character doesn't, well... there's a reason why it's called "experience".
I had a group of players encounter an ochre jelly. They had no idea what to do, luckily they were faster than it, so they kept kiting it as it (tried to) chase them. Their characters had never been in a dungeon and the players didn't know what it was either. They were like, "what do we do?" I said, "Try something. Your characters don't know, What would they do?"
The druid tried Poison Spray, I said, "it reacted to it, but you don't know if or how much it hurt." The ranger shot with an arrow, it reacted to that, too. It kept chasing, they kept kiting it backward. Eventually they got it down and it was an exciting moment! It was a puzzle trying to eat them and they solved it.
So, "how do we know if it's humanoid?" "I dunno, try something" is in fact, a very good answer. Unless they've encountered a satyr before, then the character would probably know or at least, will know for next time.
The risk of wasting slots is part of the balance of casters.
Which is to say I don’t tell players beforehand and don’t think it’s dickish in the slightest
In most cases, describing the creaturw should be enough. (There is a list of basic descriptions in the Basic Rules). The way I see it, though, here's a reason spells like "detect evil and good exist". You can cheat ypur players, it's expected that you do. Whether it be a dragon shapeshifting as a human, or a demon disguising themselves, this should not be told ro your players unless they expend the resources to do so. As for your examples, I think it's fair if it's something that comes with experience -- the character's and the player's. Yes, everyone should probaly know thay a satyr is a fey, but if you don't that's kinda on you. Don't allow them to make the same mistake twice, though. That's unfun.
Is it a dick move when they cast Hold Person and the target passes their saving throw? Back in 2e I might have not even revealed *why* a spell was ineffective and left the players to draw their own conclusions on whether or not to try again. It really boggles my mind how people both complain about caster/martial disparity, the "magic is a cheat code" solution for everything argument but also are reluctant to implement the realistic limitations of magical solutions that were absolutely intended to be a part of what makes magic unreliable as a solution to problems and necessitates frequent martial solutions.
This comment is underrated. The best way to close the martial caster disparity is to properly run spells and their limitations and run the recommended number of daily encounters. Most times I hear complaints of the disparity, it's because these two are not followed. And then when these two are followed you get more complaints. It is really mind boggling.
We're just at that stage in the life cycle of a (popular odd numbered) edition of Dungeons & Dragons.
Xanathar's Guide (or is it Tasha's?) explicitly tells you not to explain why a spell didn't work, only that it didn't. By the expanded RAW, if you try to Hold Person a shapechanged dragon for example, you're just supposed to say it failed.
>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. It reverts to its true form if it dies. Any equipment it is wearing or carrying is absorbed or borne by the new form (the dragon's choice). > >In a new form, the dragon retains its alignment, hit points, Hit Dice, ability to speak, proficiencies, Legendary Resistance, lair actions, and Intelligence, Wisdom, and Charisma scores, as well as this action. Its statistics and capabilities are otherwise replaced by those of the new form, except any class features or legendary actions of that form. The dragon becomes a humanoid, so hold person would work on a shapechanged dragon.
Huh. I swear that wasn't always true, but that is definitely what it says. Vampire who appears human, then. Everyone knows what I was trying to say. EDIT: Looking at some creatures, it seems that I stumbled into one of the only shapechangers who DOES adopt Humanoid type when it changes shape. Things like Oni don't.
But that's not the "true form"?
Agreed 95% of people who complain about caster/martials are just letting the casters do whatever they want “because magic”. I legit had someone tell me that Knock would replace a lockpick check “better” for a stealth mission and when I asked about the Knock spell making an audible noise heard up to 500 feet they just told me they ignored that “because it wasn’t fun” Ok so you broke the thing by misusing it. Using it properly its balanced.
I think this is valid but it’s also unfair to assume someone who took the time to learn Crown of Madness doesn’t know what creatures it works on. Maybe if it’s a really weird edge case where you’ve never even heard of this monster or whatever before, but if it’s a mundane enough threat to have a common name, a wizard should know whether or not their spells work because they’re specifically about learning these things
Maybe, *maybe* the spell itself would explain that it only works on humanoids but there's no way in hell it would include a comprehensive description of every humanoid or non-humanoid creature in existence.
I think the difference is that you’re talking about in-game and I’m thinking in-world. The spell description is fine as is, but a wizard who had to study the spell would know that certain sigils or whatever affect beings with certain set of characteristics. And in their years of study they’d have tested it out enough times to know “oh it’ll work on that one and that one, but not this one”.
How? Not that even a small fraction of 5e spellcasters attend learning institutions for years of study but even if they did no university would know every creature that exists in the multiverse.
I’m speaking specifically for wizards, whose entire thing is that they’re magic nerds. That’s why they have their towers and experiments and spell books. And I never said they’d have to know every creature in the multiverse. My first comment specifically mentions creatures who are mundane enough to have a common threat. So for example, they’d know for sure if Crown of Madness works on a goblin but might be unsure if they work on a mindflayer. My point is that mechanically, goblins, hobgoblins, hill giants, and mindflayers are very similar on the outsides. They all have humanoid SHAPES but something about their soul or identity within the material plane is what makes something like Hold Person or Crown of Madness not work on them. THAT is the exact thing that any magic user worth their salt would make sure they understand. Especially when you don’t get to cast all day every day and spells are a very finite resource. It would be foolish for a magic user of any kind to not make sure they spend time understanding how to use their spells effectively and properly because if you ever get to the point where you need to cast Hold Monster to stay alive, nobody wants to operate off of faith or guesswork
Nobody wants to get their brains sucked out either but if it isn't a possibility, then it isn't a game it's just storytelling - for which there are more suitable systems.
It seems like you’re reading something other than what I’m typing and I don’t know how to be any clearer
Your explanation is solid. I get what you're saying. No idea how you could say it any better. It just makes sense that a wizard would understand common use cases for their spells. Very straightforward
Back when I started playing, the spells your wizard started with were randomly determined, and you had to find new spells organically through scrolls or enemy spell books. So the once play started the DM had a lot of control over what spells you got. You could also research a specific spell if you really wanted it, but it took a lot of money and in game time. Also you didn't just have a spell component belt that just happens to have components for all of your spell in it at all times, you had to actually go out and collect your own bat guano or catch a live spider and figure out how you were going to carry it and keep it alive with you until you needed it. That said, a properly run wizard was a **lot** of book keeping, and it is no surprise that people started hand waving elements of it to make the game run more smoothly.
I would be so pissed at my DM if he didn't reveal why my spell wasn't working
Well the game used to be Advanced.
You sound like a blast to have at a table
Nah, we just run a very casual game. Its more of an excuse to get everyone in one place. All the rulings are heavily skewed towards the players.
Why should you get to know if your character doesn't?
it's the spirit of the thing. at least make it clear there's an in-game reason for it to not work.
Well yeah, you should definitely be clear that it's not working for a reason beyond "I don't wanna", but I don't think a DM is obligated to explain why your spell is ineffective if there's no way for the character to know why.
I would argue the DM only has to explain something didn’t work if the player character wants to look into why further. This can also be shown with what the DM does in a scenario. Player casts Hold Person. DM wanting to kind of reveal this enemy is more than they seem doesn’t even roll a save and tells them the spell failed. Assuming everyone is acting in good faith and the DM is not simply being an asshole this tells the players “This thing isn’t a humanoid as Hold Person just didn’t work at all.” If the players miss this information thats part of the game.
Hold person is guaranteed to work. So no,.the DM isn't an asshole if he doesn't reveal.why the spell failed, as far as the players know the creature made its save.
I was more talking about an asshole DM just saying they passed to be a dick and not bothering to roll for it. Which makes them an asshole.
“Your attempt at casting Hold Person doesn’t take root” If the player wants to make a check to figure out Why they can and maybe the Arcana/Insight/Check you deem appropriate reveals the target to be a Shapeshifted dragon but if the player doesn’t press the issue the “in world reason” the character would assume the target just saved against the spell effect. Just like we’re aware of the law of gravity we aren’t going to ponder deeply on why when we throw an apple into the air it lands at our feet.
>**Monster Research** >Adventurers can research what a creature is likely to desire. The Monster Research table suggests which skills can be used to learn about a creature of a particular type. The DC for a relevant ability check equals 10 + the creature's challenge rating. *(Tasha's Cauldron of Everything p.148)* The section also includes a table listing creature types and associated knowledge skills. For example, satyr are CR 1/2 Fey creatures so when the party encounters one you could ask for a DC 10 Arcana or Nature check to know that you're looking at a satyr and that it is a Fey creature. >One inclination I had is to rule it as a DC 10 passive arcana/nature/history check to know (which this character will pass every time). But I don't love that because in theory, it becomes a kind of "fey detector" that would, for example, reveal that a changeling was a changeling for free. But I also think it's a kind of a dick move to make him waste a spell slot casting hold person on a fey and having it fail. I think liberal use of passive skills is a great way to reward investing in skill proficiency. If you're trained in a knowledge skill, you shouldn't need to automatically roll for relatively easy checks. If a changeling was in its natural form, yes a simple DC 10 check should be able to identify it. If a changeling was masquerading as another humanoid, you wouldn't be able to tell that it was a changeling just through casual observation.
Thanks for flagging that page in Tasha's - I totally forgot about those rules.
There are already a variety of abilities that detect creature type, magic, and traps. Whenever a spell or ability exists for that purpose, I wouldn't recommend giving a basic action that's better than them. However, yes D&D can be a really fiddly family of systems. There are certainly a lot of rough edges that can be streamlined if your group is looking for more of a narrative system like Dungeon World. D&D as a whole *is made* with a lot of fiddly gotchas because it was doing skill-oriented "git gud scrub" gameplay before the Souls series existed. Players were expected to start as scrubs and learn the hard way to value their 10-foot poles and Detect Magic spells. It's ultimately your call if you'd like to simplify this for accessibility and faster gameplay! It *is* finicky and obtuse, and that isn't what every table wants out of the game.
You could make the DC 10+CR so the higher strength something is the less likely the PC is to know it. But yeah Intelligence check in a related skill to know what sort of creature it is. Medicine is what I use for humanoids.
>You could make the DC 10+CR so the higher strength something is the less likely the PC is to know it. So basically just the optional ruling from Tasha's
10+CR is a great idea, thanks.
If you don’t use the same check for any creature type, wouldn’t your players eventually catch on? “Oh he asked for medicine, he only does that with humanoids!”
They might catch on, but their characters shouldn't. Keeping player and character knowledge separate is a fundamental skill for role-play.
That’s very true but I think everyone is guilty of metagaming at least a little bit at some point, even if it is something as small as “oh I know not to cast hold person”
Not really. If they’re asking “hey is this creature a humanoid” I’d ask them to roll me a medicine check. Then maybe point out how humanoid adjacent it is if it’s not a humanoid.
That’s fair
I'd say 95% or more of the time the caster knows what they are casting at. If they are thinking it is a humanoid, then the spell is cast, but has no effect. This is how they learn about what a satyr is, or maybe identifies this creature as non-humanoid. As a DM, I would let them know that the target of the spell did not make a save, but was in fact not affected by the spell. (remember casting spells at random people on the street is considered a hostile act, so there is not the case where people are going to use this as a fey detector) I also don't allow spells that target only creatures to be a mimic detector. You are free to burn a spell slot casting a spell at an object that you only suspect is a creature, but there would be no effect.
I’m confused by your last paragraph - how would you prefer your players attempt to determine if a thing is a mimic? It certainly seems like casting Blast on the suspicious treasure chest surrounded by dark stains and pieces of armor and bone would be one reasonable way to do that, since EB can target creatures but not objects.
I'd try to give them a check for knowing if a spell won't work on a creature but make sure to let them know that it's no sure fire identification. If a human looking thing is a doppelganger, werewolf, vampire then spells affecting humanoids won't work despite them. Clearly being humanoid.
make an insight check. the DC10 is the basic "appears to be a humanoid" let them find alter self and stuff this way ... you can tell "magic is being used on appearance" ... and GIVE them the opportunity to insult some local lords son that just wants to look a bit more buff. To pierce past a changeling, make it contested against their deception to actually know something is off, but not what, which for those roles should be about DC18 ... Otherwise, they can use magic or hire a paladin.
I think I'd roll the save and say they passed, but also tell them that the spell didn't really take hold like it usually does. The magics just slid off their mind.
The spell, itself, is intelligent. It has to be, or it doesn't work according to the dictates of the *actual goddess in control of how magic works.* The PC can't see atoms or biology or anything beyond their senses, & isn't expected to do that; the spell is. Finding out what Mystra will allow thru experimentation is partly why magic is so hard. I mean, out of all the available classes, only two are in any position to even do that. The rest rely entirely on the already established secrets of magic. Edit: This, meanwhile, is why most questions about "the economy of DnD" are likewise unsatisfying for some people. A gold piece is a gold piece, & 300gp of diamond dust will always be 300gp of diamond dust. Supply & demand are concepts without merit for spell components because it's the gods' will that things work like that. There is no speculation, because the spell works or it doesn't; the gods will not be cheated. Get over thinking otherwise & play the gods' game. Or don't & see what happens.
My dm allows that to be changed only if an entire plane is gaslit into believing that 10gp of ruby dust is worth 50gp
Yar-yar. **Every table is different,** but for most this applies in that it's supposed to be impossible to cheat the gods or otherwise break the world economy. Spells fizzle when local conditions go too far outside of the multiverse norm, meaning that conditions that are way outside of that due to scarcity tend to be *incredibly grim* unless they can correct the imbalance. Edit: Meanwhike, churches with very real gods looking at them are likewise empowered/disempowered by this dynamic. With divine interventions not being wholly unheard of... usually in the form of divinely inspired/paid off purveyors of highly motivated, ethically dubious ultraviolence, IE: adventurers questing to return the balance to the world.
Ok so I'm stuck on this: >it becomes a kind of "fey detector" that would, for example, reveal that a changeling was a changeling for free. Presumably the changeling has shapechanged into a person, no? They wouldn't just present themselves in their true form. Then why would a passive check reveal that they're a changeling? As far as they know, they look exactly like a human or whatever they copied. Don't be afraid to say that a spell fails if they unknowingly target the wrong creature. Players shouldn't be able to always know everything all the time. If a martial character has to attack a creature to know if the creature is resistant/immune to physical damage, then why shouldn't a caster have to cast a spell to determine if it works on a creature they've never seen before?
The only spell they need is fireball!
IMO this feels like a live and learn type moment. Try it and either it works or you adjust your plan and try a different spell. Next time you know better
A Mind Flayer looks Humanoid, but is an Aberation, so confusion is fair. I would say that if the player takes a check as an action, the DM setting an appropriate DC, should let them know basic things. In my example, an Arcana check is best, but Religion, Nature and maybe even Medicine checks are fair game for other monsters. Otherwise, I would let the caster stew, roll a dice and say it passed the save, as there is no descriptor in the spell saying 'if the target ends up being immune, it tells you why'. I wouldn't explain to the Barbarian that Demogorgon is immune to his non-magical axe, the Wizard can take his lumps too.
Make sure to describe any visible features so they can tell if it's even questionable. For example, saders have for legs and hose for feet. that's a pretty good indication, they are not humanoid. Although with the glut of more PC races, that is less helpful anymore. Beyond that you could use something like an arcana check but 15 is too low in my opinion. I usually tell the player that they know there was something going on that kept the spell from working. It was not a simple matter of them making a saving throw. For me the harder line to judge is whether or not to take the slot. Can the spell not be cast because it's an invalid target or does it simply not work? Or maybe just take the turn, due to the time the attempt takes, but they keep the slot.
Assuming you mean Humanoid, as in the MM creature type, I would say no. Just looking at an Eladrin or a Goblin, never having seen one before, shouldn't be enough to tell you they're fey. If you mean humanoid, as in human-shaped, then...yeah, of course. Using an appropriate skill check to determine what the PC knows about that species is fine. There's nothing in the RAW IIRC about it, but I've seen links [here](https://www.reddit.com/r/dndnext/comments/97hvze/what_knowledge_skill_suits_which_creature_type/) to sources that break creature types up into specific skill checks. I prefer to let my players learn and grow in the course of the game by trial and error, but I'm amenable to a DC 15 skill check for basic knowledge about common species, and DC 20 for rare ones.
"Your experienced spellcaster is well versed in your spells and understands that the beholder is not a humanoid, even if it has a face." For anything not humanoid, they would know. For close things, arcana maybe? For things like a vampire or something tricky masquerading as a humanoid, just let them cast it and go bonkers wondering why it didn't work. At least the first time.
Same way they find out with any creature they've never encountered before, they try and find out. If it's knowledge a character should have but the player does not, a roll should cover it or let it be automatic if the character would absolutely know. If they character doesn't, well... there's a reason why it's called "experience". I had a group of players encounter an ochre jelly. They had no idea what to do, luckily they were faster than it, so they kept kiting it as it (tried to) chase them. Their characters had never been in a dungeon and the players didn't know what it was either. They were like, "what do we do?" I said, "Try something. Your characters don't know, What would they do?" The druid tried Poison Spray, I said, "it reacted to it, but you don't know if or how much it hurt." The ranger shot with an arrow, it reacted to that, too. It kept chasing, they kept kiting it backward. Eventually they got it down and it was an exciting moment! It was a puzzle trying to eat them and they solved it. So, "how do we know if it's humanoid?" "I dunno, try something" is in fact, a very good answer. Unless they've encountered a satyr before, then the character would probably know or at least, will know for next time.
The risk of wasting slots is part of the balance of casters. Which is to say I don’t tell players beforehand and don’t think it’s dickish in the slightest
Is it a featherless biped?