How to handle Knowledge about monsters

[Wheels]

So I'm currently DMing for some friends and need some help with a common request from my players. Everytime they encounter a new type of monster, they want to roll knowledge to see what they know about the monster (for example knowledge dungeoneering when they underground).

I'm at a dilema with this and wanted to know what your opinions are about this. For one, if a player invested alot of points in a skill, it should be useful and they should get information but at the same time, I dont think they should know everything about every monster they encounter just because they have enough skill points to roll a 25+ on every roll. So how do you deal with this situation?

I dont think just incrementing the DC is solution just because as they level up those roll's will get higher and higher and feels awkward having a higher DC just because they have more skills invested. Any help is appreciated.

ty all

[OldTrees1]

I don't think they should know everything about every monster they encounter just because they have enough skill points to roll a 25+ on every roll.
You should unpack this. I presume it is not being against a high knowledge check resulting in a well informed character, so I suspect there are nuances that we would need to know about your preferences/position.


Personally I have harder to know details have higher knowledge DCs than easy to know details (this is not caused by HD or CR). Humans being bipedal is something very easy to know but Mind Flayers being bipedal is more obscure knowledge. Dragons being 6 limbed creatures is easy to know but basilisks being quadrupeds is more obscure. In any case knowledgeable characters are knowledgeable.

[Eloel]

I'm at a dilema with this and wanted to know what your opinions are about this. For one, if a player invested alot of points in a skill, it should be useful and they should get information but at the same time, I dont think they should know everything about every monster they encounter just because they have enough skill points to roll a 25+ on every roll. So how do you deal with this situation?

Why not? Unless the monster is a particularly rare specimen (to the point of "one of a kind", or "created by a particular wizard that hasn't revealed them yet"), the knowledge skill shows that they have studied the monsters.

Any information that can be known, should be known.

[torrasque666]

Possibly....possibly a DC bonus based on type. For example, Arcana covers Dragons, Constructs, and Magical Beasts. Depending on how common those creatures are and how readily research would be available for the type (ie, if dragons are rare in your world, there might not be much information available on them to know about without finding it out yourself, and as such would have a higher DC than a Magical Beast) Alternatively, use the creatures HD/CR (higher of the two) as the base, and work from there.

[Wheels]

You should unpack this. I presume it is not being against a high knowledge check resulting in a well informed character, so I suspect there are nuances that we would need to know about your preferences/position

I really think it takes away some of the discovering part when they enconter a new type of monster. If they always know everything, in my perspective, fights become more boring and less interesting.

[Pex]

Borrow from Pathfinder.

DC is 15 + CR on the appropriate knowledge check. Character must have at least 1 rank in the skill. If you make the DC you get to ask the DM one question about the monster. For every 5 you beat the DC you get another question. As for questions to ask, it could be HD, special attacks (Energy drain, petrification, breath weapon, affliction effect [stun, sickness, fear, etc.], etc.), special defenses (DR, SR, Energy Resistance/Immunity, etc.).


I really think it takes away some of the discovering part when they enconter a new type of monster. If they always know everything, in my perspective, fights become more boring and less interesting.

It's possible for characters to know stuff in character that players would not. The knowledge check is the mechanic to determine this.

[Gildedragon]

Well first don't negate players' choices when creating a character. If they really invested in that it means it is their way to contribute to the party

Second the srd has a very good guideline:

you can use this skill to identify monsters and their special powers or vulnerabilities. In general, the DC of such a check equals 10 + the monster’s HD. A successful check allows you to remember a bit of useful information about that monster.

For every 5 points by which your check result exceeds the DC, you recall another piece of useful information.
So at less than 10+HD give them a name (especially if it is obvious what it is: a lion, a dragon, a zombie) maybe give them a few options, a large cat; probably a lion or some sort of leopard. The behemoth before you is a sort of Leviathan Dragon or Tarrasque
10+HD (I'd suggest CR instead but houserule there) actual name, type (along with type atributes -though if the PC is serious about knowing things they ought have those themself-) and possibly a tidbit of their subtype or attacks or special abilities Or ability scores "terribly strong and very smart or their alignment or a feat... Essentially one line or so of their monster entry
At each 5 extra you give a bit more

[AnachroNinja]

Here's my go to thinking in this:

Would you personally recognize a picture of a giraffe? Lion? Ape? Rhino? I'll grant that modern technology makes images more easily found, but at the same time, you're (presumably) not a zoologist. And that's what knowledge skills represent, genuine and deliberate study of an area of information. I feel comfortable stating that a zoologist would likely recognize 95%+ of the animal species on the planet, with an exception for insects which are extremely diverse.

That's all a basic success represents, recognizing a creature on site. I can identify a rhino, tell you that is horn is valuable, they have an aggressive temperament and can be territorial. They can charge at speeds of 30+ miles per hour and weigh over a ton. That's just random info picked up over time in life.

So is it really unlikely that a trained expert can recognize most things on site? Not know everything about it, just recognize it.

On a side note, my favored house rule is to give natural 1s a -10 on the check. This insures that there is a chance of failure, but that really easy checks like an orc will still almost never be failed.

[Gildedragon]

I really think it takes away some of the discovering part when they enconter a new type of monster. If they always know everything, in my perspective, fights become more boring and less interesting.

The players invested in those skills because for them it is more fun to know.
Don't prioritize your fun over the party's fun.
Unless the check is very good PCs won't know everything
If the monster is rare or new raise the DC by 5, give the PCs basic information (it seems to be a magical beast of some sort, it's fangs look not unlike a snake's fangs, or those of other venomous creatures; it looks similar to a lich and is probably related) and let the PCs name it. They spot the similarities to other creatures they know, and because of that knowledge and the context they find the creature in and how it looks they can fathom stuff of this new thing

[Andezzar]

I really think it takes away some of the discovering part when they enconter a new type of monster. If they always know everything, in my perspective, fights become more boring and less interesting.If a character knows a lot about creatures, he knows a lot about creatures. So the player should get that information. This however does not mean that all the other players get that information. So the knowledgeable character might know that the monster is vulnerable to acid and fire, but and regenerates other damage, that does not help his party until he tells them. Compartmentalizing information can make the game more "fun".

Also don't forget that identifying a creature is 10+HD. Just knowing that reptilian creature is a basilisk is only DC 16, but for every additional bit of information (petrifies by gaze, can see in the dark, etc.) the DC increases by 5.

[Eloel]

Would you personally recognize a picture of a giraffe? Lion? Ape? Rhino? I'll grant that modern technology makes images more easily found, but at the same time, you're (presumably) not a zoologist. And that's what knowledge skills represent, genuine and deliberate study of an area of information. I feel comfortable stating that a zoologist would likely recognize 95%+ of the animal species on the planet, with an exception for insects which are extremely diverse.

Just to put this into context:

There are about 65000 described vertebrate species. 95% means around 62000 species - not really easy to do, but certainly possible for someone who dedicates his life to doing it.

Given that we're roughly 3rd level experts, even at 16 Int and Skill Focus(Knowledge: Nature), that's a +12 to check. If we need 15 to identify, that's around 90%. Certainly within the right ballpark.

[OldTrees1]

I really think it takes away some of the discovering part when they enconter a new type of monster. If they always know everything, in my perspective, fights become more boring and less interesting.

1) Yes, playing a knowledgeable character means forgoing the character discovering what they already have studied. If the player regrets making their character knowledgeable then offer them a chance to retrain.

2) The knowledge check to know about Drow is much lower than to know about Drizzt. This species vs NPC gap can result in a lot of room for discovery.

3) Some of the discovering part still remains in that the Players tend to not know the details that you are informing them that their characters know. Few players know the Illithid life cycle, so someone playing that Dungeoneer will still feel discovery when they learn what their character already knew.

4) Having a dynamic fight taking place on/around varied terrain between interesting characters can still result in interesting fights even if the characters know about each other.

5) If even after all of this, you still miss the characters being ignorant about the monsters they encounter, then make that known to your players. You should not invalidate their investments but they might surprise you and change their investments to help make the game more enjoyable for you.

[Red Fel]

I really think it takes away some of the discovering part when they enconter a new type of monster. If they always know everything, in my perspective, fights become more boring and less interesting.

Bottom line, it sounds like you dislike how the Knowledge skill can disrupt your game.

My advice to you, then, is to make a house rule about what it can or cannot do, and tell the players in advance of the game. That's fair and reasonable.

Otherwise, the players will expect Knowledge to work as-written. And how it works as-written is that, if you succeed on the appropriate Knowledge check, you recall a bit of information on the creature in question; by succeeding by a wider margin, you recall more. If you, as DM, have issue with players optimizing around Knowledge in order to recall large amounts about the creatures they face, then you can either change the rule in advance of the game, or deal with it.

That said, Knowledge checks do not - or at least, should not - render an encounter boring. Learning that a Medusa has a Petrifying Gaze ability is all well and good; the PCs know not to look her in the eyes. But how does that render the encounter boring when they're fighting in a darkened cave, when the PCs can barely see five feet away, and the enemy could burst from any direction? A Knowledge check will reveal that Azers deal fire damage in melee. (Heck, your eyes will reveal that; those dudes are literally on fire.) But the encounter will still be amazing if it is fought against a pack of Azers, while the PCs are doused in oil. And all the Knowledge checks in the world can't prepare the PCs for Tucker's Kobolds. My point is that, if you're worried that PC Pokedexes are making your encounters boring, there are other things you can do that will make them awesome.

[Necroticplague]

Even getting a 25+ on the check doesn't give you everything. Remember how knowledge checks work:

In many cases, you can use this skill to identify monsters and their special powers or vulnerabilities. In general, the DC of such a check equals 10 + the monster’s HD. A successful check allows you to remember a bit of useful information about that monster.

For every 5 points by which your check result exceeds the DC, you recall another piece of useful information.
So, even for the most feeble creature in existence, a 25 only gives you 3 pieces of information. This can be relatively minor things like "It's a goblin. They are skilled at sneaking around, and are natural at riding other creatures". In fact, Knowledge Checks give startlingly little information if you go straight by the rules. Especially if you take advantage of what the players already know by giving them facts they already suspected, thus avoiding providing any additional useful information, but still letting them feel good about verifying what they suspected.

Also, the DCs do scale on their own, as HD tend to inflate to preposterous levels as CR increases.

[Eloel]

"Useful Information" is admittedly very vague, but saying obvious or non-useful things is a way of being a ****ty DM.

Compare

"This is an elf, and your useful information is that they are good at finding secret doors".
"This is a blue dragon, and they have scales."
"This is a tarrasque, and it has a lot of hp."

with

"This is an elf, immune to sleep and paralysis"
"This is a blue dragon, and they have a lightning breath weapon"
"This is a tarrasque, can regenerate from all lethal damage"

[Gnaeus]

I really think it takes away some of the discovering part when they enconter a new type of monster. If they always know everything, in my perspective, fights become more boring and less interesting.

Remember also that that is the only mechanism to translate OOC knowledge into IC knowledge. If you are a player of 10 years, it's kind of painful to have to relearn the same basic lessons game after game, especially with characters with godlike intellects.

"Oh, a blue dragon? Dang it, we have only fought reds, blacks and greens. Ok, fine, I cast a lightning bolt, did I learn it has SR or that it is immune to electricity?" is not a fun voyage of discovery. It is a tedious process of marking off tick boxes on a spreadsheet to verify that OOC knowledge is now IC.

[Necroticplague]

"Useful Information" is admittedly very vague, but saying obvious or non-useful things is a way of being a ****ty DM.
Obviously. Obvious information is what Spot checks are for, and non-useful is flat-out ignoring the rules.

[AnachroNinja]

I've always preferred the house rule of letting the players ask a question for every 5 points over. It helps reflect what information is both important to them as characters, and what might pop into mind as being relevant to that situation. A knowledgeable wizard is much more likely to know about a creatures SR then it's DR in my opinion, and that's probably what he'd ask about, unless the party fight fighter has been desperately and ineffectually flailing away at it anyway. Then he might ask about that.

[OldTrees1]

I've always preferred the house rule of letting the players ask a question for every 5 points over. It helps reflect what information is both important to them as characters, and what might pop into mind as being relevant to that situation. A knowledgeable wizard is much more likely to know about a creatures SR then it's DR in my opinion, and that's probably what he'd ask about, unless the party fight fighter has been desperately and ineffectually flailing away at it anyway. Then he might ask about that.

This is a great houserule. How do you handle things the players don't know they don't know?

[Forrestfire]

As a DM who greatly likes unique, refluffed, or new monsters, how I tend to do it is to look at the character's ability with Knowledge as not only what they've studied, but what they know, and can deduce.

So when I throw a group of cybernetic monsters made of a dragon-type flesh embedded within modular metal plates at the players, our archivist/wizard theurge rolls a 40 on his Knowledge check and goes something like:

I've never need these before, but look at the craftsmanship on the machinery! It's obviously not completely mechanical, otherwise it wouldn't have those magic seals on the sides. When you stabbed it right there, that's not oil. The way it reacted with the stone floor is a telltale sign of dragonblood! The way they're moving together makes them seem like they're communicating perfectly, so it's probably a hivemind! Those color-changing lights on their faceplates are firing lasers, and that's similar to [insert wizard with an Arcane Thesis] here. I bet that they work on the same principle!

And OoC, I tell him that these are refluffed Ambush Drakes with the Living Construct subtype and some extra abilities that he's made an educated guess at. If I had been using the rules as written, I'd have told him that they were dragon-typed with the Living Construct subtype, and listed some of the other abilities, rather than telling him to go look up Ambush Drakes, but that's mostly because at the time I didn't want to figure out what to say, and the massive check felt like it fit.

[AnimeTheCat]

The way I have handled this exact issue in previous games I've been DM for was by going through ahead of time and creating a table of sorts with various DCs and what they would know, similar to the bardic knowledge table:

10: Common easily identifiable information; Dragons have tough scales providing a measure of natural armor (nothing very specific)
20: Things you could find out through basic study; Dragons breath weapons by type (blue/lightning, Red/Fire) after all, there are many kinds of dragons
25: More specific things; typical fighting style, combat abilities, slightly more what to expect while fighting
30: Very creature specific things; age and it's granted abilities, spellcasting types, etc.

When I went through and followed this formula I was able to very easily put information out to the player and it made it simple for me. It requires a bit of planning, but once you do it, you can typically look at the MM entry and place things within those categories quite easily and quickly.

[Zanos]

6 skill ranks per level is a non-minor investment to cover every creature type, and you're going to need close to max ranks to reliably make checks, since the DCs are going to scale with you as high CR monsters tend to have large amounts of hit dice.

I don't think it's unreasonable for someone with large amounts of skill ranks invested into it to have a pretty damn good idea of the abilities of what they're fighting are. Accidentally hitting a monsters immunity or high save can result in serious pain in a system where wasting your action is severely punished.

When I DM, if someone makes a knowledge check, I just tell them they can look up the monster. I don't tell them about any class levels, but they can probably infer that the guy with a holy symbol is a cleric.

[Mennayr]

I use a ramping DC for Knowledge checks.

Base DC is 10 + CR for common monsters, and 15 + CR for rare monsters. Making this gives them general info (where they live, the most common stuff from tales about them etc.), then for every 5 they beat the DC I let them pick an additional group of abilities to know about. For example they might want to know the weaknesses a monster has, or what sort of special defenses it might have.

[Deadline]

I've always preferred the house rule of letting the players ask a question for every 5 points over. It helps reflect what information is both important to them as characters, and what might pop into mind as being relevant to that situation. A knowledgeable wizard is much more likely to know about a creatures SR then it's DR in my opinion, and that's probably what he'd ask about, unless the party fight fighter has been desperately and ineffectually flailing away at it anyway. Then he might ask about that.

I've done something similar. Basically I take the check result, determine how many bits of information they get, and ask them OOC "You get X pieces of information, what kind of stuff do you want to know? Special Qualities, Defenses, attacks?"

The usual questions I get range from things like "Does it have SR?" to "What are its three most potent types of attack?"

It's worked pretty well for years now.

[Godskook]

I really think it takes away some of the discovering part when they enconter a new type of monster. If they always know everything, in my perspective, fights become more boring and less interesting.

Is chess more boring or interesting because we know 100% of the rules? I'd argue more interesting. Is Hearthstone, MtG, League of Legends, or any other combat-based game more boring or more interesting because you can literally study every single interaction? Again, I'd argue more interesting.

The thing is, known rulesets are more interesting to strategize because your decisions are meaningful and informed. Poorly understood opponents are more boring to strategize because there's no way to make anything close to an informed decision.

Otoh, its very interesting to discover new things. In a very shallow game world, where elves are elves and lycans are lycans, and dwarves are dwarves, etc etc, throwing new mosnters at the party is a cheap way to add discovery to the game. However, it adds very little strategic interest, as players can't really improve their strategies specific to your campaign. Otoh, if your world itself has depth of discovery, such that every new monster is interesting because every new monster is part of the plot, then you add discovery while enabling strategic depth. Sure, some elements of discovery is great among new monsters, but generally, you're ruining the enjoyment of combat to put it there.

[rrwoods]

I'll reiterate something said earlier:

Don't put your fun above the players' fun.

If you don't want knowledge checks to be able to determine the properties of creatures, you can always houserule it. But if you do, you should allow your players to (at a minimum!) reassign their skill points, and possibly remake any character build decisions that depended on those points being allocated they way they were.

[Darth Ultron]

I dislike knowledge checks in general. But most players love them for the obvious reasons.

I just tell them the most basic stuff about the monster. Generally whatever amount a player thinks is a lot. I greatly avoid game rule information and use more fluff. So the monster can ''shoot fire'' not ''use the spell-like ability of produce flame''.

And I have always used the ''for every five points you can ask a question''. This works out so well as most players ask bad, useless or obvious questions and ''waste them''. For example most problem jerk players will ask ''what is the monsters weakness'' and as most monsters don't have lame video game weaknesses I can say ''none'' and laugh.

There is the fan made Monster Lore Compendium (https://docs.google.com/spreadsheets/d/1Nz3NeC2w51jBHXsnilLbbWF3zvu52OXz-NSZShhEVao/edit?pref=2&pli=1#gid=0) and it's a great starting point.

[Fizban]

Take a look at the later monster manuals that actually list the information to give out on knowledge checks: they're incredibly stingy and unreliable, and you can use them as an example for earlier monsters without those entries. You don't get specific information, you're likely to get information you don't even need or will find out when the monster attacks anyway, and so on.

Red Fel mentions the PHB definition as a boon, as Necroticplague already mentioned it's actually even more restrictive: making the check you get 1 "useful" bit of information, +1 per 5 over the DC, but the DM is the only arbiter of what you recall so answers such as "undead don't eat, sleep, or breathe, and that's your 3 bits" while obviously unfair are perfectly legal. Later MM sidebars often skip the most important/obvious abilities or push them to higher DC, but they do always give creature type traits standard.

Knowledge checks represent an extremely wide array of information on a topic and only include the most prominent academic data about monsters, as you'd discuss them in a classroom or a general textbook. For the kind of "read me the stat block" info that players want, you need to compile it yourself via trial and error or ask someone who has. Quasi-medieval information tech (hand written books only) is not as good as the internet. The equivalent of a Zoologist would be someone with Knowledge: Monsters, a DnD knowledge specialist is more like someone who's studied everything but zoology.

I haven't codified it, but I imagine a dual-approach would be better. You can make lore checks which tell you things like "use cold iron for demons and silver for devils," and/or you can make a specific check which will get you it's identity and most notable features as judged by the DM (one check per round, one specific check per monster and one roll for each bit of lore you try to remember between some time cycle). Maybe allow a question in place of a notable feature, but I'm still not sure if that's always a good idea. I'd also increase the DC for specific checks if needed so you shouldn't get more than 2-3 bits on the highest rolls. So people with mid-level skills can take a guess at what they're fighting and roll for lore, while high level skills can identify the monster and warn you of the big stuff so you roll the right lore checks.

The key is the "lore" checks, which are easy and cover stuff that experienced players know but others might not. Cold iron and silvered weapons are sold everywhere, the check to remember what they're used for should be easy. Dragons are color coded and terrify most people, their energy types should be well-known. You don't have to keep a log of the basic lore you're allowed to use as a player because the rolls are just for people that aren't informed to get freebies. As mentioned above, actually hitting an immunity really sucks, and the game really doesn't expect you to do it. If the encounter is designed with that bait in mind and they fail their checks, then sure, but normally it shouldn't happen. Adventuring is an actual profession after all. If the characters have ever hit a magic item shop and talked to the owner they likely have an idea of what magic they can afford, what it's useful against, and that's plenty of excuse for knowing all sorts of things.

[wheeeels]

First of all, thank you for all the replies.

I never put my fun above my players fun and like i said in my initial post, I dont want to penalize my players for investing in skills, but at the same time i dont want to just hand them the monsters manual for them to see the beast (my players dont read the monster's manual). Of course them knowing everything about the monster is not the end of the world and normally fights dont rely on them being ignorant, but I like to bring a lot of new monsters to the table and make unique but logical (based on the monsters descriptions) combinations.

I was not aware of the DC+HD (i'm going with DC+CR) and it seems fair so i'm going to use that on my games.

[LudicSavant]

I always found the default RAW for knowledge about monsters problematic.
Person sees a wyrmling red dragon: "Oh, hey, that's a red wyrmling dragon, it's weak to ice and resistant to fire"
Same person sees a great wyrm red dragon: "I have no idea what that thing is or what elemental weaknesses or resistances it may have."

[Necroticplague]

. For example most problem jerk players will ask ''what is the monsters weakness'' and as most monsters don't have lame video game weaknesses I can say ''none'' and laugh.


That seems highly disingenuous. While most monsters might not have a video-game style "takes extra damage from some source" type of weakness (though some do), they generally do have some factor about them that makes them easier to beat if you're aware of it (low touch AC, which of its saves is the lowest, a low grapple mod, that it's land speed is 1/4th its swim speed....) or have defenses overcome by something, which seems a valid answer to "what's it's weakness" (i.e, what overcomes their DR or regeneration).

[Ashtagon]

So I'm currently DMing for some friends and need some help with a common request from my players. Everytime they encounter a new type of monster, they want to roll knowledge to see what they know about the monster (for example knowledge dungeoneering when they underground).

I'm at a dilema with this and wanted to know what your opinions are about this. For one, if a player invested alot of points in a skill, it should be useful and they should get information but at the same time, I dont think they should know everything about every monster they encounter just because they have enough skill points to roll a 25+ on every roll. So how do you deal with this situation?

I dont think just incrementing the DC is solution just because as they level up those roll's will get higher and higher and feels awkward having a higher DC just because they have more skills invested. Any help is appreciated.

ty all

There's a couple of competing issues, two of them social issues and only one of them a game mechanical one.

First, the social ones. You as GM want monsters to be puzzles in which the players get surprised by whatever special power(s) or weakness(es) the monster has. Perhaps this is to say later "you should have used sonic damage since its weak to that" or "bet that paralysing venom bite surprised you huh?". That may be fun for the GM, but for the players, it's "I got you good with something you weren't allowed to know about!"

On the other hand, the players are maxing out their knowledge skills in order to look at it and say "yep. It's a lesser spotted purple dragon. It has X-ray vision, laser breath weapon, and is allergic to poppy seeds. Also, this one is in love with that dragon who lives over in the next valley." It seems as if the players basically see the skill as a way to avoid the narrative and the onerous tasks of finding out stuff. Which is fine for the routine stuff, but sometimes, the story is supposed to be "what's this weird thing we've never seen before?" Perhaps they don't enjoy the "find out stuff" story, in which case it's better to avoid that story, rather than try to turn it into a DC vs. skill arms race.

Third, the mechanical stuff. Knowledge skill (in as much as it pertains to recognising monsters) means you know what a lesser spotted purple dragon is, what it looks like, and what abilities and weaknesses it typically has. A few details about its mating habits, life cycle, and preferred habitats too. That's it.

It won't let a PC distinguish between two closely related monsters that look basically the same but have wildly differing powers (such as the notorious nilbogs from 1st edition, which are thankfully absent in later editions). A lich can quite easily impersonate a zombie should it choose to do so. If a monster has a template that doesn't change its appearance, it won't tell you it has that template, or even what that template might be. You could get a free extra check if it uses an ability it "shouldn't" have. The skill also won't tell you about any class levels a critter has. That's probably the single easiest way to surprise PCs with monster abilities, and one that trivially thwarts Knowledge checks.

And it never lets a player inspect the statblock.

[Telonius]

Personally? A single rank in the appropriate Knowledge check lets you know all the information in the "Types and subtypes" entry. Knowledge, as mentioned, gets you a piece of useful information for every 5 that you beat the DC. I ask the players what they want to know: a special attack, a special quality, or a general piece of information about a particular ability score or saving throw (i.e. Orcs tend to be kind of dumb and uncharismatic; Ogres tend to have low reflex saves).

[OldTrees1]

First of all, thank you for all the replies.

I never put my fun above my players fun and like i said in my initial post, I dont want to penalize my players for investing in skills, but at the same time i dont want to just hand them the monsters manual for them to see the beast (my players dont read the monster's manual). Of course them knowing everything about the monster is not the end of the world and normally fights dont rely on them being ignorant, but I like to bring a lot of new monsters to the table and make unique but logical (based on the monsters descriptions) combinations.

I was not aware of the DC+HD (i'm going with DC+CR) and it seems fair so i'm going to use that on my games.
Sounds good but consider this:


I always found the default RAW for knowledge about monsters problematic.
Person sees a wyrmling red dragon: "Oh, hey, that's a red wyrmling dragon, it's weak to ice and resistant to fire"
Same person sees a great wyrm red dragon: "I have no idea what that thing is or what elemental weaknesses or resistances it may have."

Someone that knows what a Red Wyrmling is should have a good guess at what a Great Red Wyrm is but knowing the specific differences would be harder(the DC+CR check). So when more common/weaker versions of a monster exist, give them some common/general information if they pass the lower DC but not specifics about the rarer/stronger version unless they pass the higher DC.

[AnachroNinja]

It is deeply disturbing to me that there are DMs in this thread that seem to relish the opportunity to trick their players about what their skills do...

[Deadline]

It is deeply disturbing to me that there are DMs in this thread that seem to relish the opportunity to trick their players about what their skills do...

Indeed. I suppose that I have to (apparently) qualify my method by stating that I err on the side of the players, and I don't act like a jerk by trying to deny them information. My method breaks down if you look for any little opportunity to screw with the players.

As to the interesting encounters bit, I'll just echo what Red Fel said. Encounters aren't boring because the PCs know stuff about the monster (usually the opposite). Boring encounters aren't suddenly made less boring by having a mystery monster, that just makes them boring and confusing. Good encounter design makes for interesting encounters. As others have stated, leveraging lighting conditions, terrain, and having objectives needing to be accomplished can all make for a much more tense and exciting encounter. Heck, just having a neat backdrop for an encounter can make things more exciting.

[InvisibleBison]

I always found the default RAW for knowledge about monsters problematic.
Person sees a wyrmling red dragon: "Oh, hey, that's a red wyrmling dragon, it's weak to ice and resistant to fire"
Same person sees a great wyrm red dragon: "I have no idea what that thing is or what elemental weaknesses or resistances it may have."

I think that people have a tendency to over-apply the DC 10+HD rule for Knowledge checks. It's supposed to be used for learning specifics about individual monsters. For general information about monsters or categories of monsters, the other set of Knowledge DCs should apply - 10, 15, or 20 for easy, moderate and hard questions. So a DC 10 Knowledge (arcana) check reveals that dragons are big scaly flying monsters with breath weapons, DC 15 lets you know what energies each color uses, and DC 20 reveals other, more obscure traits about each breed. The DC 10+HD check, on the other hand, lets you know what unique attributes a given dragon has. For a wyrmling, that's not much. A great wyrm, on the other hand, has damage reduction, spell resistance, spellcasting, spell-like abilities, and frightful presence, plus whatever they've picked up from feats, magic items, and such like that differs from dragon to dragon.

[Jay R]

There's also this consideration. Even if you make the roll, and you know all about the creatures, can you see them well enough to identify them?

DM: You see some humanoids coming at you.
Player1: I roll on my knowledge (Underground)
DM: What are you trying to figure out?
Player: What these monsters are, and how they fight.
DM: They are vague humanoid shapes moving in the shadows toward you. Size is not clear.

A couple of rounds of archery, then the DM passes a note to Player 1, which says, "Now that you can see them a little, you're pretty sure that they are goblinoids of some sort."

Melee begins, then when the person who made the knowledge roll is engaged, the DM passes another note: "They are too small to be hobgoblins."

Next round, another note: "Now that they are clearly in your light. You can tell that they are blue, so your knowledge skill tells you to expect psionic attacks."

This makes the roll significant, without it preventing some surprises in combat.

[Andezzar]

The DC 10+HD check, on the other hand, lets you know what unique attributes a given dragon has. For a wyrmling, that's not much. A great wyrm, on the other hand, has damage reduction, spell resistance, spellcasting, spell-like abilities, and frightful presence, plus whatever they've picked up from feats, magic items, and such like that differs from dragon to dragon.That however is true for all dragons of a certain age (i.e. HD) it is not specific to a particular specimen. So this could just as well fall into the easy, moderate and hard question categories.

The problem with dragons and knowledge checks is that dragons work differently than other monsters. Most monsters have a typical set of abilities (i.e. the MM entry) and have some form of advancement (either just hit dice or something more elaborate like Hellhound -> Nessian Warhound). The lower DCs are for the creatures that people are more likely to encounter.

The age categories of dragons however grant HD and thus increase the DC, but the age categories are not tied to the likelihood of an encounter with such a dragon. How many wyrmling dragons roam the countryside to be met by adventurers or other people? Do Great Wyrms generally go about and erase all knowledge about them? No, this is just a specific case where the X+HD/CR system does not work. Given the iconic status of dragons in fantasy games, I think the better way to change the system for dragons would be to always use the wyrmling DC but give more information for each 5 points the DC is exceeded according to the actual age of the dragon. Identifying a flying lizard should not be too hard no matter its size, but knowing whether a flying lizard of a certain age/size has already gained the ability to cast spells should be more obscure.

[Telonius]

Knowledge on Advanced-HD creatures should probably be its own separate thing, whether for Dragons or anything else. Otherwise you get into silliness like knowing what a 7-HD Griffon is, but suffering a lapse if you see a 21-HD Griffon. (Or not being able to identify a Human if he happens to have 20 hit dice of Fighter, for that matter).

[AnachroNinja]

With dragons I always handle it by providing the relevant information on abilities that a dragon of the age category that their roll WOULD be able to identify. Great wyrm and you only rolled high enough for an adult? You know the information you'd get for an adult and lower but the special abilities of a truly ancient dragon are beyond your ken.

[denthor]

You could always try this:

You made your knowledge check said monster this is what you get in the first 6 seconds Round.

Now that you've used your round up the monster attacks do you want to continue making those checks to remember what you know about the monster.
Player Response why yes I want to know more about the creature.

Your response you get this your rounds done monster attacks

And if you really want to be mean have it written on a piece of paper so that not only does he use his rounds to figure out what this picture is he can't tell the rest of the table when it is unless he uses more rounds to do so
For each round the player uses them they're useless knowledge skill monster attacks a party and then he gets to tell the party and stayed there for six rounds to give three bits of Information

[Deadline]

You could always try this:

You're too late, being a jerk to your players was already suggested at least twice.

[Gildedragon]

You could always try this:

You made your knowledge check said monster this is what you get in the first 6 seconds Round.

Now that you've used your round up the monster attacks do you want to continue making those checks to remember what you know about the monster.
Player Response why yes I want to know more about the creature.

Your response you get this your rounds done monster attacks

And if you really want to be mean have it written on a piece of paper so that not only does he use his rounds to figure out what this picture is he can't tell the rest of the table when it is unless he uses more rounds to do so
For each round the player uses them they're useless knowledge skill monster attacks a party and then he gets to tell the party and stayed there for six rounds to give three bits of Information

Whut? Speaking and knowledge checks are free actions... Did I misunderstand what is being said entirely? Did I miss a joke here?

[AnachroNinja]

No you understood fine sadly. There's a bevy of DMs apparently who like to punish their players for the sake of *mystery* and their idea of fun combats. It's baffling but there it is.