A number of people have been talking about metagaming lately. Someone was even nice enough to give a definition of it stating that 'it's the player's real life knowledge that influences the character's decisions when the character wouldn't have had that knowledge at all'... or something like that. Close enough.
Some metagaming is to be expected, I think. If you sit at a table with decades worth of collective knowledge, it's impossible not to see a skeleton and reach for a bludgeoning weapon, or swear when you don't have one on hand. And mostly I'm okay with that. It means a bit more work on my end if I'm DM-ing to get monsters that have a few variations that the players haven't seen and mostly they appreciate the variety.
I'm also very guilty of this kind of meta-knowledge. And it's hard for me to switch off and go "my character wouldn't know this." I get so excited about knowing that I forget I'm supposed to not know.
But this is not the metagaming that I've been recently challenged with. What do you do with someone who actively reads the material prior to a session so as to gain maximum benefit?
I've asked a couple of people and most of the responses I've gotten is to "confront and kick out". Or to actively change the game so that it's different from the book. That's fine and well, but it's a lot of work to do for someone who is effectively cheating. Do I reward them with my additional time and effort by actively working against them? Or do I admit defeat and have them spoil the game?
I'm currently running a game of intrigue. So the secrets aren't necessarily where the chest is hidden or where the secret passage leads. It's people who have very deep and dark secrets. It's having to interact and not know whether you're really encountering the truth. It means that if you spoil someone with additional knowledge, it's not limited to a room, but to the entire game, all the politics.
Couple of years ago I played a game of Dragon Heist with a group of people. One player innocently looked for pictures on google for a particular character they encountered in the game. She's an artist and I don't believe she meant any harm or went out to read up on anything. But, as these things go, wiki was able to supply her not only with the pictures she desired but the secrets I was keeping from the party. While she didn't say anything to the group, except for admitting to me that she fucked up, it tainted the game entirely. Because she couldn't switch off this meta-knowledge. And so every time they encountered that NPC, she would behave in a peculiar fashion, which made everyone suspicious and so they took the route of caution and were denied the direction of interest.
That is what I'm worried about with this particular game I'm running now. And that is why I don't know what to do about it. I enjoy the player's interactions, mostly. I have no qualm with the person and, while it's still very early to shift from 'acquaintance' to 'friend', the potential exists. But I also know he's not going to stop. And that is a problem I don't have a current solution for.