I have talked about his topic in the past. My current desire to rekindle it was sparked after I skimmed the 5e release of Scarred Lands Creature Collection and noticed that a number of monsters have seemingly arbitrary types. For example, the flay beast is [beast] and the blood reaper is [aberration] even though both are giant aggressive praying mantises created by the same titan.

The problem with the 5e taxonomy mechanic is that it is hierarchical when it does not need to be. The definitions of several types are vague, inconsistently applied, and often arbitrary. In some cases one may be unable to determine the most appropriate type for a monster: it could fit into multiple types, is more appropriate with multiple types, or the monster's concept may not fit into any of the types given in the rulebook. This is a problem because the taxonomy mechanic is relevant for any effects that specify a target's type, such as healing, enchantment, and summoning spells, or the ranger's favored enemy.

By comparison, 13th Age, FantasyCraft, and Pathfinder 2, among others, dispensed with hierarchical taxonomy mechanics. Under their mechanics, a monster may have as many types as appropriate to its concept.

For example, monsters like the chimera and hydra are typed as [monstrosity] when real world academic sources clearly refer to them as dragons.

D&D takes most of its monsters from Indo-European mythology but its taxonomy mechanic is hardly appropriate for them. Mazes & Minotaurs (Greek myth setting) limits its taxonomy to animates, beasts, folks, monsters, and spirits. Trudvang (Scandinavian myth setting) limits its taxonomy to beasts, beings of the mist, creatures of nature, dragons/wurms, jotuns/tursirs, and trolls.

I question the need for a taxonomy mechanic at all. How necessary is it, really? What is the purpose of having it? Are there more intuitive ways to implement it? Why does it exist in-universe as part of the laws of physics/magic/study?

If anybody could help me out with this, I would really appreciate it.

Quote from: BoxCrayonTales;1123451I question the need for a taxonomy mechanic at all. How necessary is it, really? What is the purpose of having it? Are there more intuitive ways to implement it? Why does it exist in-universe as part of the laws of physics/magic/study?

If anybody could help me out with this, I would really appreciate it.

     As I understand it, it's basically there to handle type-specific abilities once the game goes beyond a small fixed list of monsters--what's undead and thus can be turned, what can be charmed by charm person, what counts as a 'giant-class' enemy for OD&D/1E rangers, etc.

    Open-ended descriptors a la BECMI and other games do seem to do the same work without forcing the "this creature must be A OR B OR C" problem.

Quote from: Armchair Gamer;1123452As I understand it, it's basically there to handle type-specific abilities once the game goes beyond a small fixed list of monsters--what's undead and thus can be turned, what can be charmed by charm person, what counts as a 'giant-class' enemy for OD&D/1E rangers, etc.

    Open-ended descriptors a la BECMI and other games do seem to do the same work without forcing the "this creature must be A OR B OR C" problem.

Yeah, I think this is accurate. I first saw this in full-blown implementation in D&D 3rd due to the necessity of categorizing all the monsters to "make it easier..." for the DM to determine what spell/effect affected what. AD&D had ye olde ranger vs. "giant-class" and Charm Person, but both of those had a definitive list spelled out for the DM; the classification wasn't blanketed over every single monster. Obviously I think the original way is easier because you don't end up shoehorning monsters into those arbitrary divisions. Like wtf are dragons? They're dragons, the end. They might have a list of rules about things that apply directly to them, which makes it seem MORE difficult than just the basic "magical beast" (or whatever) descriptor, but you shouldn't be running a dragon as a DM without knowing what you're doing with it in the first place or at least have a good understanding of the rules. System mastery sort of went out the window as time has moved on, and don't even talk about the DM making decisions about how things work in his world...

Just more ranting about how RPGs actually keep getting more convoluted and hard to understand because designers try to implement things to make it easier for idiots to run games. Like I cannot even imagine trying to run Pathfinder, and I ran D&D 3.5. Pathfinder just looks even more complex, and I hard a hard enough time trying to remember the myriad of rules for crap like what monsters were affected my sonic damage, what spells would affect undead, whatever. Just a lot of overly complex nonsense.

Quote from: Brad;1123475Just more ranting about how RPGs actually keep getting more convoluted and hard to understand because designers try to implement things to make it easier for idiots to run games. Like I cannot even imagine trying to run Pathfinder, and I ran D&D 3.5. Pathfinder just looks even more complex, and I hard a hard enough time trying to remember the myriad of rules for crap like what monsters were affected my sonic damage, what spells would affect undead, whatever. Just a lot of overly complex nonsense.

I think at least as much (probably more) of the motivation is an attempt to standardize rules and eliminate interpretation to facilitate tournament, convention, and organizational play.

Quote from: Bren;1123486I think at least as much (probably more) of the motivation is an attempt to standardize rules and eliminate interpretation to facilitate tournament, convention, and organizational play.

Not debating that at all; pretty sure it started with RPGA and kept going to whatever it's called now...Adventurer's League? But AD&D claimed to do this and it still required a fair referee. D&D 3.X and beyond can be run with someone who blindly follows the rules. I liken it the having an umpire in baseball vs. using a camera/computer. No matter how sophisticated the technology gets, until it understands the spirit of what constitutes a strike, the computer will never be as good as the umpire.

Quote from: Brad;1123475Ybut both of those had a definitive list spelled out for the DM;

That ceases to work the moment a new monster is released that wasn't included in the list.  Does its creation subsequent to the material mean that it should be included, or should be excluded?  Are you going to compare publishing dates to determine, and then do further research?  Seems like a waste of table time.

There are some abilities (like talk to animals) that you want to know, every time you meet a creature, if you could use it.  Technically, we're all animals but the intent of the spell is to talk to (relatively) unintelligent animals like horses and cows, not orcs and dragons.  Since the spell only works on a small subset of all monsters, all monsters, present or future need a place where you can hang a tag identifying whether speak with animals works or does not work.  Trying to put example creatures in the spell without a definitive list is still going to end up being confusing.  Is a gorgon really just a big cow that turns people to stone, or is it a totally different kind of monster that doesn't communicate through moos?  If you meet an Evee or a Pickachu, (or a shocker lizard), should that spell apply?  

Trying to reduce the text bloat by using a single word entry (like UNDEAD) to make it clear how it interacts with a whole slew of rules like drowning, having a heart ripped out, decapitation, turning, magical healing, etc, is much more efficient than trying to put those type of special rules in a text description.  

I do think that having multiple types is a good thing.  If you have a half-dragon/half-merman there's no problem giving it the dragon type/humanoid type/water subtype/fire subtype.  That's potentially a little complicated, but much less so than trying to explain how that type of creature interacts with all the existing rules as well as spells that haven't been written yet.

Quote from: Brad;1123475Yeah, I think this is accurate. I first saw this in full-blown implementation in D&D 3rd due to the necessity of categorizing all the monsters to "make it easier..." for the DM to determine what spell/effect affected what. AD&D had ye olde ranger vs. "giant-class" and Charm Person, but both of those had a definitive list spelled out for the DM; the classification wasn't blanketed over every single monster. Obviously I think the original way is easier because you don't end up shoehorning monsters into those arbitrary divisions. .

The problem with that is the list had to be updated for every monster book. By listing the monster type in the monster stats, you don't have to do that.

I think it can be used well. Its just that it seems more often these tags get applied willy-nilly.

5e D&D is a good example.
A Stirge is rated as a Beast. You know, a mundane animal.
While a Dire Wolf or Worg is not. Despite being more mundane than the stirge.

And trying to shoehorn square creatures into round holes.

The main problems are the hierarchy and then using the labels for different purposes within the same tags.  D&D tries to have it both ways, using the tags both as an exclusionary group mechanism and as a way of organization.  

If it were me, and I was going to "fix" the 5E implementation, I'd drop the explicit organization entirely, keeping only the exclusionary groups.  Then let the GM infer whatever organization they wanted from the resulting labels.  Do that, and you can easily have multiple tags on monsters, or not, as it suits you.  Then if you want to make a hydra a monstrosity and a dragon, that's fine.  If you prefer monstrosity and beast, that works too.  Nothing wrong with just one of them, either.  Depends on the setting.

Quote from: deadDMwalking;1123505That ceases to work the moment a new monster is released that wasn't included in the list.  Does its creation subsequent to the material mean that it should be included, or should be excluded?  Are you going to compare publishing dates to determine, and then do further research?  Seems like a waste of table time.

Quote from: JeremyR;1123509The problem with that is the list had to be updated for every monster book. By listing the monster type in the monster stats, you don't have to do that.

Like, what? The only person who needs to know if it'll be affected or not is the DM, unless it makes sense for the player to know (DM tells the ranger player xvarts count as goblinoids for his damage bonus). You guys are making it sound like it's an insanely ridiculous chore to have to update a list somewhere because five years later someone made up a couple new monsters.

I'll concede that there's merit to "monster type" in theory, but in practice...

It's clumsy when you get to edge cases, which seem to be ubiquitous in D&D. Half the fucking monsters in the 5th edition MM seem to be put into categories that are questionable. For instance, ankheg is a large monstrosity, but so is a basilisk. Per the text, it's a "catch-all category". Why is a giant spider just a beast instead of a monstrosity? An ankheg could arguably be just as natural a creature as a giant spider because there's nothing particularly crazy about an animal that spits acid (ants?). It's just really big. But so is the spider. A fucking basilisk turns people to stone by looking at them. That is definitely UN-natural, so why aren't they aberrations like beholders instead of monstrosities? Why are pegasuses (pegasi?) celestials instead of some sort of magical beast? MY MIND IS BOGGLED!

Quote from: Steven Mitchell;1123522The main problems are the hierarchy and then using the labels for different purposes within the same tags.  D&D tries to have it both ways, using the tags both as an exclusionary group mechanism and as a way of organization.  

If it were me, and I was going to "fix" the 5E implementation, I'd drop the explicit organization entirely, keeping only the exclusionary groups.  Then let the GM infer whatever organization they wanted from the resulting labels.  Do that, and you can easily have multiple tags on monsters, or not, as it suits you.  Then if you want to make a hydra a monstrosity and a dragon, that's fine.  If you prefer monstrosity and beast, that works too.  Nothing wrong with just one of them, either.  Depends on the setting.

I agree with you. Not EVERY monster needs a label, and in fact it's mostly irrelevant except to know what sort of stuff Turn Undead works on and if an Orb of Dragonkind will work on a hydra. In both cases, the DM is the ultimate authority, anyway, and in the hydra case it could depend entirely on how the DM envisions hydras in his game. In the Palladium FRP, they're somewhat intelligent (although still pretty dumb); I always liked that and made hydras the offspring of Tiamat that she spawned when she was drunk or something. So the Orb would work. If you're going with the Hercules hydra, then it probably wouldn't.

Quote from: Brad;1123525In both cases, the DM is the ultimate authority, anyway, and in the hydra case it could depend entirely on how the DM envisions hydras in his game.

I can always decide that Hydras are or are not dragons in my game, but I don't want to HAVE to.  The whole point of using a published set of rules is that I don't HAVE to make hundreds of decisions balancing consistency, the intent of the rules, the challenge of the game, and the fun of the players.  

If the players want to use an orb of dragonkind on a hydra, that might be a clever play, but it also might leave me short of prepared material.  Am I really being completely unbiased when I say 'no, that doesn't work'?  

Applying the rules as written shields me from accusations of favoritism or antagonism.  If I say 'hydras are not dragons, it doesn't work' and the rules back me up, there's no chance that the players are going to feel like I'm being unnecessarily limiting on their creativity.  Alternatively, if it doesn't say and I say it does work, some players might feel I'm pulling my punches and making things TOO easy.  

I can ALWAYS change the rules, no matter what, so not having a rule that comes up is NOT a defense of the quality of the rules.  

There are a lot of questions about type that the DM may not want to have to answer on a case-by-case basis, and there is CERTAINLY a chance for unintended consequences if they do.  What creatures should a druid be able to turn into?  Should they be able to turn into a pegasus, a giant spider, an ankheg, a beholder?  Using type lets you answer that question consistently from table to table, and if you decide differently for whatever reason, it's clear you're using a variant rule.  There's value in that.

Quote from: deadDMwalking;1123531What creatures should a druid be able to turn into?  Should they be able to turn into a pegasus, a giant spider, an ankheg, a beholder?  Using type lets you answer that question consistently from table to table, and if you decide differently for whatever reason, it's clear you're using a variant rule.  There's value in that.

Table to table consistency is predominantly a benefit for some type of organized play. Outside of that, I prefer  having table to table variety. How does your PC know, with absolute precision, whether a hydra is or is not related to a dragon? And I like the notion that the druid can try to turn into any of the creatures you named, but they don't know for certain what will happen (with potentially dangerous consequences for a bad roll on a bad guess). If they want predictability they should stick to truly mundane animals like a stag, boar, or wolf just like Gwydion did in the legends that are the original source material for that particular druid ability.

Quote from: Brad;1123475Like wtf are dragons? They're dragons, the end.

The problem is that the distinction between dragons and any other reptiles isn't intuitive, especially once you start getting into comparative mythology. I only ever found the one easily understood explanation of what a dragon is, and medieval bestiaries list dragons as a type of serpent rather than a separate category. Even the word "dragon" is derived from the Ancient Greek word for snake.

It strikes me as arbitrarily and more than a bit silly that, for example, an arrow of dragon slaying deals extra damage against dragon turtles and wyverns but not against snakes, flying snakes, lizards, crocodiles, turtles, hydras, etc. I don't think the ancient cultures who invented the stories of dragons would have made such a distinction.

Quote from: Brad;1123475I cannot even imagine trying to run Pathfinder

Me neither.

Quote from: deadDMwalking;1123505There are some abilities (like talk to animals) that you want to know, every time you meet a creature, if you could use it.  Technically, we're all animals but the intent of the spell is to talk to (relatively) unintelligent animals like horses and cows, not orcs and dragons.  Since the spell only works on a small subset of all monsters, all monsters, present or future need a place where you can hang a tag identifying whether speak with animals works or does not work.  Trying to put example creatures in the spell without a definitive list is still going to end up being confusing.  Is a gorgon really just a big cow that turns people to stone, or is it a totally different kind of monster that doesn't communicate through moos?  If you meet an Evee or a Pickachu, (or a shocker lizard), should that spell apply?  

The idea of talking to animals comes from myths and fairytales that made very different assumptions about the world than D&D. Talking to animals was a skill like any other language, not a spell that arbitrarily lasted for five minutes. Animals didn't have fixed low intelligence but were described talking as eloquently as human beings even among themselves, because humans instinctively anthropomorphize things that way. You can see this in more recent fiction about talking animals, like Babe, Charlotte's Web, and The Wild Thornberrys.

D&D trying to depict animal intelligence based on what they read in Wikipedia is needlessly complicated for what is supposed to be a game about fantasy. Real life understanding of animal cognition is rudimentary at best and the arbitrarily realism in D&D is both unrealistic (as we really have no idea what such communication would be even if it was hypothetically possible, which it isn't) and undesirable (as it is an unnecessarily convolution to a game meant to be played for fun).

Here's a much simpler take on it: animals have languages of their own. Every species has its own language and may speak to other species in an animal lingua franca. If you learn an animal language, such as by being a beastmaster or a princess or eating part of a dragon's heart, then you may talk to any animal that knows that language.

Or whatever.

Quote from: Omega;1123517I think it can be used well. Its just that it seems more often these tags get applied willy-nilly.

5e D&D is a good example.
A Stirge is rated as a Beast. You know, a mundane animal.
While a Dire Wolf or Worg is not. Despite being more mundane than the stirge.

And trying to shoehorn square creatures into round holes.

The definition for [Beast] doesn't specify that it is mundane only. In fact, "mundane" is an arbitrary quality. For that matter, the definitions rely on having a modern Western education so that you know what an "ecology" is when medieval scholars had no concept of it. Medieval scholars thought wolves were literally demons from hell and that there were no consequences whatsoever for exterminating them, when nowadays we know that wolves are necessary to keep deer from overpopulating. Medieval scholars had ideas about everything that we consider laughable now.

The stirge, dire wolf, and worg never existed in reality. (The real life dire wolf is nothing like the D&D monster.) Why would any of them be typed as [Beast] or not? Because some of them are arbitrarily "mundane" by your personal standards? How do you define "mundane" and determine what does and doesn't qualify? Why is that distinction on the same level as distinguishing construct, living, and undead? Why would that be baked into the in-universe laws of physics so thoroughly that it applies in the way that the game rules say so?

The centaur and griffon are typed as [Monstrosity] when in Greek myth they were considered perfectly natural and not monstrous in the least. Centaurs were considered human beings, not just literally because they were half-human but socially too since they were invited to weddings. Griffons were natural predators who lined their nests with precious metals, laid eggs with agate shells, had feathers than could cure blindness, etc.

The Snaiad aliens don't exist in reality, but they are written as though they could exist in reality. They operate under real physics and biology without any magic whatsoever. Would they be typed as [Beast] or not?

The game's taxonomy is annoyingly arbitrary in that regard because it not only operates on a variation of the appeal to nature fallacy but can't even decide what is and isn't natural in the first place much less keep itself consistent.

Quote from: Steven Mitchell;1123522The main problems are the hierarchy and then using the labels for different purposes within the same tags.  D&D tries to have it both ways, using the tags both as an exclusionary group mechanism and as a way of organization.  

If it were me, and I was going to "fix" the 5E implementation, I'd drop the explicit organization entirely, keeping only the exclusionary groups.  Then let the GM infer whatever organization they wanted from the resulting labels.  Do that, and you can easily have multiple tags on monsters, or not, as it suits you.  Then if you want to make a hydra a monstrosity and a dragon, that's fine.  If you prefer monstrosity and beast, that works too.  Nothing wrong with just one of them, either.  Depends on the setting.

I prefer using a taxonomy mechanic that feels intuitive for most people, rather than operating on arbitrary game logic that only make a twisted sort of sense to people who have internalized D&D lore.

What if I wanted a non-arbitrary and intuitive way to decide whether something is a dragon or not? Well, the simplest option is to use a list of traits that dragons typically have. A hydra would be a dragon, not just because Greek myth lists it as one, but because it fits multiple dragon criteria.

I dislike using the supernatural/natural distinction because it starts breaking down when applied to fantasy settings where the supernatural may be commonplace, or even medieval bestiaries where plenty of natural creatures had properties that seem supernatural to us now (e.g. the bezoar coming from the stomach of an ordinary goat and curing most diseases/poisons). At best I could replace it with "exemplary", e.g. depicting dragons as the exemplars of amphibians, reptiles, and birds who can do the same things but simply better in every way. E.g. a snake can spit venom or a frog can have toxic skin, but a dragon can exude a miasma that poisons the land around it.

Quote from: Brad;1123525It's clumsy when you get to edge cases, which seem to be ubiquitous in D&D. Half the fucking monsters in the 5th edition MM seem to be put into categories that are questionable. For instance, ankheg is a large monstrosity, but so is a basilisk. Per the text, it's a "catch-all category". Why is a giant spider just a beast instead of a monstrosity? An ankheg could arguably be just as natural a creature as a giant spider because there's nothing particularly crazy about an animal that spits acid (ants?). It's just really big. But so is the spider. A fucking basilisk turns people to stone by looking at them. That is definitely UN-natural, so why aren't they aberrations like beholders instead of monstrosities? Why are pegasuses (pegasi?) celestials instead of some sort of magical beast? MY MIND IS BOGGLED!

What is even the difference between an [aberration] and a [monstrosity]? Ignoring whether the types are applied consistently, the definition for [aberration] basically says they are aliens from Lovecraft land. Is the basilisk an alien from Lovecraft land?

The whole "unnatural" criterion doesn't make sense, either. It's not possible to universally define what is and isn't natural, especially since we can't even define what natural is in itself. Why would a basilisk be unnatural? You can make one by incubating a chicken egg with a snake IIRC. While an odd instance of spontaneous generation (which turns grain into mice and meat into flies), it doesn't strike me as distinctly unnatural. At least not unnatural enough to be as different from a regular lizard as an alien from Lovecraft land. Wizards can turn people to stone, too, but that doesn't make all wizards aliens from Lovecraft land.

(EDIT: Wait, why are we distinguish beasts and magical beasts to begin with if we aren't distinguishing humanoids and magical humanoids? A basilisk is no more different from a lizard than a sorcerer who can cast flesh to stone is from a non-sorcerer.)

The pegasus being a celestial seems to be a reference to Greek mythology, where Pegasus was the demigod son of Poseidon and Medusa. The Gorgon Medusa, a woman with snakes for hair, gave birth to a winged horse.

Quote from: Brad;1123525I agree with you. Not EVERY monster needs a label, and in fact it's mostly irrelevant except to know what sort of stuff Turn Undead works on and if an Orb of Dragonkind will work on a hydra. In both cases, the DM is the ultimate authority, anyway, and in the hydra case it could depend entirely on how the DM envisions hydras in his game. In the Palladium FRP, they're somewhat intelligent (although still pretty dumb); I always liked that and made hydras the offspring of Tiamat that she spawned when she was drunk or something. So the Orb would work. If you're going with the Hercules hydra, then it probably wouldn't.

As I said before, Greek myth literally defines the hydra as a type of dragon. It's a pretty intuitive classification, I would think.

Quote from: deadDMwalking;1123531There are a lot of questions about type that the DM may not want to have to answer on a case-by-case basis, and there is CERTAINLY a chance for unintended consequences if they do.  What creatures should a druid be able to turn into?  Should they be able to turn into a pegasus, a giant spider, an ankheg, a beholder?  Using type lets you answer that question consistently from table to table, and if you decide differently for whatever reason, it's clear you're using a variant rule.  There's value in that.

Alternately, you could scrap the poorly designed shape shifting mechanic and let druids build the statistics and traits of their forms using a point buy mechanic or something else that is internally balanced rather than letting them arbitrarily assume the form of any monster with the [beast] type. For example, the tressym has spell turning and therefore isn't balanced as an option for wildshape (not that the magic system was ever balanced to begin with, but I digress).

Quote from: Bren;1123532Table to table consistency is predominantly a benefit for some type of organized play. Outside of that, I prefer  having table to table variety. How does your PC know, with absolute precision, whether a hydra is or is not related to a dragon?

Because D&D is the only source that states the hydra isn't a dragon? How do you even define a dragon? By a list of criteria? Arbitrarily? Why do you define a dragon that way? (See my section at the bottom of this post for my analysis.)

Quote from: Bren;1123532And I like the notion that the druid can try to turn into any of the creatures you named, but they don't know for certain what will happen (with potentially dangerous consequences for a bad roll on a bad guess). If they want predictability they should stick to truly mundane animals like a stag, boar, or wolf just like Gwydion did in the legends that are the original source material for that particular druid ability.

Why do you even want to limit druids from assuming the forms of animals that don't exist in reality (or whatever the distinction is supposed to be)? Is it a matter of game balance? Do you feel like being arbitrary? I have no problem if you want to be arbitrary, but in many cases I feel people are arbitrary without realizing or acknowledging their unconscious biases.

As I said before, I think a toolkit for building a wildshape is better than the current rule which is just begging to be abused by munchkins.

---

[/HR]

Since it keeps coming up, I'll list the dragon traits from myth and how they're a better way of categorizing dragons than the arbitrary D&D distinction.

The common traits of dragons are: reptilian attributes, flight, connection to water, supernatural powers, and toxic breath or fumes. The rarer traits are: connection to the weather or natural phenomena, avian attributes, guardians and emissaries, connection to deities and status. These aren't just materialistic descriptors, but have spiritual symbolism too.

Dragons have reptilian attributes, but are distinguished from other reptiles/archosaurs* by their amazing powers like super-strength or toxic breath. There shouldn't be any reptilian magical beasts, monstrosities, or whatever the taxonomy is using in X edition: these should all be dragons. Monsters like the basilisk, behir, chimera, hydra, naga, etc should be categorized as dragons because they fit the criteria.

* Like the scansoriopterygids or pterosaurs. These weren't known to exist in medieval times. We could speculate similar fossils were discovered and lost to history after inspiring myths of dragons, as often speculated by anthropologists.

Although in real life birds are more closely related to crocodiles and turtles than either are to snakes or lizards, mythical birds like the garuda, phoenix, roc, simurgh, and thunderbird are not classified as dragons in the academic sources I consulted. Presumably because they don't have primarily reptilian attributes and the associated symbolism, even if dragons could have chimerical features like fur or feathers in addition to scales. I'd be more than happy to classify all of these mythical birds as dragons if that ever became relevant, but the distinction between scales and feathers is intuitive enough that I don't see the need to apply it as mandatory.

Quote from: Bren;1123532Table to table consistency is predominantly a benefit for some type of organized play.

In some ways, but IF you want to talk to other people who play games about their experiences, having a common reference makes sense.  If someone says, "yeah, we defeated the Tomb of Horrors with no casualties the first time through - our druid turned into a Beholder and that solved a lot of problems", that's going to imply a very different type of table environment than most.  

Trying to come up with a fair mechanic on the fly for me, as the DM, to tell the player what it takes to successfully turn into a beholder is a tall order[/b.]

Maybe if I had a month to plan, but this??

to my eye taxonomic classification with rules impact first appeared in earnest in 3e. Before this there was a much looser definition of rules regarding what it means to be undead for example. I dislike the classification, if you have a sword that does extra holy damage to demons or undead the dm should let that apply as he sees fit on a case by case basis rather than have his hands tied by players arguing that a given creature has such and such type descriptors and so should / shouldn't be affected. I don't need Shao Khan to have the outsider descriptor to know that he is native to another plane and I would likely allow a holy sword vs demons/undead get its bonus damage on him as such. Now templates like vampire or lich was a great innovation, but the 3e habit of assigning a type descriptor to everything was foolish and limiting in my opinion, it gave a certain type of player room to argue all sorts of trash based on this magic the gathering creature type notion.