Unlocking Knowledge (Monster) in 5e

I run 5e D&D with a group of players that encompasses a large span of experience and knowledge of the game. We have folks who started playing in the late 70s or early 80s with Advanced D&D 1st edition; those who have at least read all the old editions, if not played them; and those who got their start more recently with 3.5e or even Pathfinder 1e. We’ve been playing together for a long time, and some of us have settled into the roles of rules encyclopedia, monster stats encyclopedia, etc.; while others remain blissfully ignorant of all but the basic rules necessary to function. When we started up with 5e, we wanted to make things as fresh as possible, so I asked those not actively trying to run their own 5e game to avoid looking through the Monster Manual, so they could be surprised by the subtle changes to the foes that they knew and loved. That worked for a while, but now that we’ve started over at level one several times now, it’s difficult to maintain that forced ignorance.

So, we’ve started hitting up against the old question of “what does my character know about this foe?”, versus “what do I know about it?”. Usually when there is a question of knowledge in game, it’s simple to make an Intelligence check and add a relevant proficiency. There was copious guidance for that sort of thing in earlier editions to the point of skills creep with more and more specialized knowledge skills being added, either officially or as widespread houseruling. On the combat front, there was the notorious Knowledge (Monster) or (Monster Lore). This was basically zoology for the dungeon crawler, and in a lot of ways it made perfect sense for someone in the adventuring profession to pursue such knowledge.

D&D 5e has tried to prune back the knowledge tree and keep things simpler and broader, but I feel there isn’t quite enough official guidance on which knowledges cover the various categories of creatures listed in the Monster Manual and its later partners. And, that’s kind of okay, because it gives us each leave to craft our own responses. Search around for guidance on the internet, and there are several DMs and designers weighing in on the subject. What follows is my personal take on handling monster lore inspired by my own internet research and ruminations.

I want to give my players a chance to use their characters’ knowledge of the foes they encounter, but I don’t want to break immersion by going too far meta-game with that knowledge. So, I don’t want to tell a player “The Dire Pig has 12d10 Hit Dice”. Nor do I want to go with a rising DC scale that unlocks more bits of the meta-knowledge, like rolling 10 or higher tells you the Hit Dice, rolling 13 or higher adds the types of attack, rolling 15 or higher adds resistances, etc. To keep it simple, I want to go with something binary, er… ternary? Either the character fails the Int check and knows nothing, or they succeed at the check and knows some general knowledge about the foe. If they have a relevant proficiency, then they also unlock some specific knowledge with a success. And, I suppose if I felt like it I could go quaternary and add that an especially low check might provide false information, but that’s only useful if I’m using secret knowledge rolls, and I don’t usually do that because I’m lazy. (Though not too lazy to look up quaternary, it seems.) The DC for the check should be governed not by a meta-game stat, like Challenge Rating, but by the rarity of the foe in the game, guided by the DM’s world building.

What would General Knowledge cover? Things you might hear about in tavern stories, around campfires, in a barracks, etc.

  • General mien and level of aggressiveness (passive, easily provoked, attacks on sight, etc.)
  • Relative toughness compared to the buffest party member
  • How they attack (bite, claws, weapons, energy, magic)

What would a relevant proficiency unlock?

  • Special senses
  • Resistances and Immunities
  • Weaknesses
  • Tactics

And I will definitely apply passive Intelligence (Knowledge) scores to those checks, to keep rolling to a minimum. They are adventurers, so knowledge of Common foes should be at the front of their minds. Assuming they care enough about their work to live through it.

Now, I just have to decide just what is Common in my world…