Using knowledge to learn about monsters

[Davelozzi]

In my opinion, one of the cool little changes in 3.5 was the rules for using various Knowledge skills to identify monsters and their special powers or vulnerabilities:

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.

At any rate, my players have heard rumors that there may be a black dragon in dungeon they're heading to and are trying to see what useful info they might know about them. I'm wondering how people set the DCs for monsters with varying HD such as dragons.

The relevant skill for dragons is Knowledge (Arcana) and the character with the highest skill bonus has a +14. So far, I've figured that taking 20, that's a check result of 34 so I've given him the basics (prefers watery terrain/swamps, breathes acid) as well as the fact that they gain additional powers as they get older, such as darkness (since they get that at juvenile age and 34 is 10 higher than the 24 DC for a 14 HD juvenile black).

At any rate, is that how other people handle this kind of situation, or is there another way to go about it that I'm missing?

 

[sledged]

If they know the approximate age of the dragon do the roll as you normally would. Otherwise, you could just have them roll (or if you like to give misinformation on failed checks, you do the roll yourself), subtract 10 from the result and give them some bit of info based on a black dragon with a HD of the result. For instance, suppose the roll check is an adjusted 35:

a) Subtract 10, 25
b) Give the players some information on a 25 HD black dragon (I'd make this information as general as possible like the basics you gave).
c) Keep subtracting 5 from this point and repeat step b until you pass the minimum HD of the dragon type (20, 15, 10, and 5).

If you want you can make the information more specific as you move down the age category.

 

[andargor]

At any rate, is that how other people handle this kind of situation, or is there another way to go about it that I'm missing?

We handle it exactly the same way. Of course, if we encounter an obscure creature from some module, the DM sometimes rules that we know nothing of this creature and no Knowledge check will help us. Other means, like divination spells, are however still useful in those situations.

Andargor

 

[Chronosome]

Man, I love the Monster Knowledge stuff.

For your dragon, I think sledged has a cool way of doing it.

 

[Elder-Basilisk]

I figure that the DC for the smallest and least HD version of the monster is the one that should be used. So, if you are making a knowledge check about Quasits when you're fighting a group of four Quasit Rog 10s, you roll against the HD of the MM Quasit and then get information based upon that roll. Of course, none of it will tell you that this one has sneak attack, evasion, and opportunist because Knowledge skills usually tell you about general types of monsters rather than specifics. For a dragon, I'd probably start very basic--basing the DC off of a wyrmling and let them know that black dragons tend to live in swamps and breathe acid. If they get high enough to get the HD of the dragon at this stage of its development, I'd give them some information specific to this stage--it has (if it does) weak spell resistance and minor magical ability. Etc. etc.

 

[Jeff Wilder]

You can't Take 20 (or Take 10) on Knowledge checks. Basically, which tidbits of knowledge about a subject a PC has stored and can recall is essentially random.

Personally, I allow doing either, to represent research, at a cost in time of a full day or 20 days, respectively.

 

[andargor]

You can take 10 on any skill. It just represents the fact that you are not being threatened or distracted.

Taking 10: When your character is not being threatened or distracted, you may choose to take 10.

I like the house rule for Take 20 and research, however.

Andargor

 

[Jeff Wilder]

You can take 10 on any skill.

Not on Knowledge. If it's not in the SRD, it's in errata somewhere. I read the rule last week.

 

[andargor]

It's not in the PHB 3.5 Errata, DMG 3.5 Errata, nor the Main FAQ 3.5.

Are you thinking 3.0?

Andargor

 

[Saeviomagy]

We handle it exactly the same way. Of course, if we encounter an obscure creature from some module, the DM sometimes rules that we know nothing of this creature and no Knowledge check will help us. Other means, like divination spells, are however still useful in those situations.

See - I'd think that rolling high enough on a knowledge check should give information even in this situation, unless this monster is truely and completely the first one to ever be encountered or conceived of by any denizen of the PC's known universe.

After all, if it's a created monster, then there DO exist writings on created monsters, and presumably the creator would have drawn on these, or someone in his employ let word slip, or someone divined something...

In short, to say "no knowledge check" requires a total, 100% information blackout. Which is very, very hard indeed.

Of course DC's of 50+ would be perfectly valid...