I wrote a blog post nearly a month ago (as of this post) addressing a comment someone left on an old playtest document for what eventually became Dungeons & Delvers: Black Book.
Basically, in the document I said that we were going to have more mythologically accurate kobolds (which we do, among other monsters), and the guy somehow took issue with that goal.
That blog post caused someone else to write a blog post about how I guess statting out monsters is "bad" because players might learn the stats, and once the players learn the stats there won't be any mystery or immersion (which for some reason gets a capital "I" but I'm not going to do that).
I don't really agree with any of it, and frankly the whole post comes across as misguided and a bit pretentious.
First things first, us going with more mythologically accurate monsters has nothing to the sales of anything or trying to solve a problem that I'm not convinced exists, and everything to do with the fact that when I compare the classic Dungeons & Dragons kobold and the kobold from real world mythology, I find the latter to be far more interesting, so instead of telling GMs "go look it up on Wikipedia" I figured I could just do some of the legwork.
If the real-world kobold was a small draconic-ish humanoid, and the Dungeons & Dragons kobold could change its shape and turn invisible and phase through stone, I'd be sticking with the D&D version.
I have to ask: what mystery? The abilities we're giving kobolds are and were “known”. We didn't just pull shapechanging and invisibility out of our ass or give them random abilities that just so happened to also be what it was said to be able to do: it's on the fucking Wikipedia entry! The Wikipedia entry that anyone can go read up on, which was again informed by what people “knew” about kobolds.
It's partially because of that that I don't think there is anything wrong with the players knowing monster stats. This is not only an inevitability of just playing the game, but is also reflected in the real world: people "knew" at least some of what most monsters were capable of. They "knew" that kobolds could change their shape and turn invisible.
(What do you do when you play a campaign and the players learn stuff, and then start up a new campaign? Do you just never use monsters you used in the previous campaign? Do you completely change everything about them? Do you move to a new town or get a new group?)
I will point out that I didn't just ask Vb if his players would have any clue how to kill a kobold, I said, "So your players have no idea what an elf or kobold can do, or how to defeat them?" He thinks they'd hem and haw and respond with "it depends", but I think it's a safe bet that even in his game elves and kobolds can simply be stabbed to death.
Really though "it depends" is valid for many groups and many monsters, even if the players know the default stats unless maybe the DM/GM only ever has the players fight them in flat open terrain.
Finally, knowing monster stats doesn't mean that the players know everything about the monster (or even most things about it). Knowing that kobolds can turn invisible and change their shape doesn't instill knowledge of their history, culture, general personalities/habits, and so on: it just means they know that kobolds can turn invisible and change their shape.
Knowing default monster stats has nothing to do with immersion: it's what the player does with that knowledge that can I guess hamper it. Like, if the player knows that kobolds can turn invisible but the character somehow doesn't (maybe the PCs are the first people to ever run into a kobold?) and still acts on that information.
If the general population knows that kobolds can change their shape and turn invisible, then the characters probably know this, too. In fact, telling the players that their characters know commonplace information even if the player doesn't actually reinforces immersion.
I don't give a shit if the players know that basilisks are so poisonous that they can turn stone to dust and kill you just by looking at you: I want to see how they handle it.
Frankly, if you need to hide stats from players to instill wonder or mystery then you're probably a bad GM. So what if the PCs know that kobolds can phase through stone: have them come across an ancient, subterranean kobold city that's been buried for centuries and only easily accessible by things that can phase through stone.
Sounds pretty mysterious to me: what was it like? How has it changed? What caused the kobold sto flee (or what killed them all off)? What artifacts/treasure/magic shit is still down there?
Dwarven Vault is our sixth 10+ Treasures volume. If you're interested in thirty dwarven magic items (including an eye that lets you shoot lasers) and nearly a dozen new bits of dungeon gear, check it out!
Just released our second adventure for A Sundered World, The Golden Spiral. If a snail-themed dungeon crawl is your oddly-specific thing, check it out!
By fan demand, we've mashed all of our 10+ Treasure volumes into one big magic item book, making it cheaper and more convenient to buy in print (which you can now do).