How much info to reveal on a successful knowledge check?

Question

My wizard is trying to use Knowledge (Planes) to determine Monster Lore of a Nabasu Demon. The DC is 10 + the challenge rating, so 18.

On a success, I "remember a bit of useful information about that monster".

My DM has us do our own rolls and own knowledge checks. Let's say the dice determine that I learn 3 "bits of useful information" about the monster. I would like to make a list of each "bit", then roll to see which I reveal. How much info should be revealed with each "bit of information"?

Examples to illustrate the question -- should each spell-like ability be an individual bit, or should the collection of spell-like abilities be one bit? Should immunities and resistances be clumped into one "bit" or be two separate bits?

There seems to be a lot of information someone could know about these demons, and I can think of at least three ways to group them into "bits". I'm not sure which to do.

• Darkvision
• Flies
• DR 10/cold iron or good
• Immunities
  • Death Effects
  • Electricity
  • Paralysis
  • Poison
• Resistances
  • Acid 10
  • Cold 10
  • Fire 10
• Spell Resistance
• Special Attacks
  • Consume Life
  • Death-Stealing Gaze
  • Sneak Attack
• Spell-like abilities
  • Deeper Darkness
  • Greater Teleportation
  • Telekenesis
  • Enervation
  • Silence
  • Vampiric Touch
  • Mass Hold Person
  • Regenerate
  • Summon

Answer 1

My current GM breaks this down into 10 (11 if you count meeting the DC) sections.

For achieving the DC, you get a name to call the creature and it's type(s). For every 5 beyond that you either select or roll for 1 of these 10 'blocks':

• Senses: Vision, Scent, ETC..
• AC: Armor Class weakness or strengths. This includes CMD.
• Saves: Weak or Strong Saves
• Immunities and Resistances
• Weaknesses: DR, Vulnerability, Regeneration
• Attacks: Strong attacks / Grab / Trip / Constrict / Rend
• Special Attacks/Defenses: Breath weapons, Auras, Gazes ETC..
• Spell-Like Abilities
• Languages and Skills
• Lore: Ecology, Organization, ETC.

This has worked generally well for the group; having a decent Knowledge check is enough to ask for vital information but having a tremendous knowledge check nets you further rewards. This has the obvious drawback of some information being significantly more valuable (I'm looking at you Weaknesses and Immunities) or entirely useless (Weaknesses of something with only DR/- or no DR, vulnerability, or regeneration).

For this reason, we as a group decided to abide a social contract; we roll d10's (rerolling duplicates) and the GM's allows further rerolls of any that are not applicable to the creature. This balances the randomness of attaining knowledge on such a variety of creatures with the power of being able to ask specific things.

Alternately, at times, we have also established character norms; for instance, the Inquisitor would always ask the same questions, in the same order, regardless of if they had an answer or not. They "studied" targets in a manner that promoted knowledge of Weakness>Immunities>Special Attacks>Senses>Strong Attacks>etc. This worked fairly well for the short time that they survived, RIP Aleksandra. It negated randomly receiving bad information but balanced it by applying 'dead spots' where no information was gained.

One additional thing is we tend to ask for meta knowledge we already have first. Weaknesses is always the first thing we ask about trolls, to establish an in-character cannon of knowledge that you need to hit them with fire or acid.

Answer 2

When one of my players succeeds on a Knowledge check, I ask them to choose one of the following:

• Information regarding the monster's attacks
• Information regarding the monster's defenses
• Information regarding any other special abilities the monster may have
• Information regarding the monster's behaviour, ecology and temperament

For every X points they beat the DC by (depends on your personal preference and the system you're playing, I'd suggest having X be between 2 and 5) I'd let them choose an additional category from the list. Even if they fail the check, I'd usually give them some vague information that their character would infer from having encountered other creatures of a similar type - e.g. "It looks demonic, so you'd guess it might have some form of Acid/Cold/Fire resistance, although you're not sure to what extent."

For their chosen category I'd be pretty thorough (possibly answering follow-up clarifications depending on what they were) but would provide vague / inaccurate / no information on the categories that weren't selected. FWIW players seem to enjoy this tactical wrinkle and it also means that two characters in the same party who both do well on their roll can pool their knowledge (choosing separate categories) without being redundant.

The main thing to bear in mind is to not slow down the session too much - give out a reasonable level of information then allow the players to ask follow-ups if they wish. The worst thing you can do is regurgitate an entire stat block for 10 minutes while they doze off and the encounter loses all momentum!

Hope that helps :)

Answer 3

Quoting directly from the core rulebook...

Check: In general, the DC of such a check equals 10 + the monster’s CR. For common monsters, such as goblins, the DC of this check equals 5 + the monster’s CR. For particularly rare monsters, such as the tarrasque, the DC of this check equals 15 + the monster’s CR or more. 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.

What kind of information (defenses, special qualities or attacks etc etc) and how much of this information you, or your GM, can reveal well...is up to the GM. At my table i use this method:

knowledge roll = knowledge DC - I give the player the type(and subtype) of the monster like undead or plant. The qualities for every type and subtype (undead are immune to mind effecting effects for example) are free in this way.

knowledge roll = knowledge DC +5 - I give the player all the previous information and i tell them the most powerful attack (or DC special attack/spell like ability) the monster has.

knowledge roll = knowledge DC +10 and more - I start give them BLOCKS of information like all the monster defenses, all the monster special attack, all the monster spell like abilities etc etc.