This is exactly how my last D&D campaign went!

That’s why I always play half elves. I mean, they’re like 60 to 80 years old. They have seen some shit. They have learned some shit. They’ve been in human society that entire time, even if they’re only physically in their early 20s.

Reasonably, I have enough local background knowledge to address myriad situations.

My low wiz eldrich knight that keeps touching blatantly cursed shit and just rolling with it.

My tiny tortle sorcerer is obsessed with putting gems in his mouth. The DM knows this. The party knows this. It makes for some very funny conflicts

Yes. It’s so annoying. A lot of good roleplaying is imagining a way your character would have/know something. Obviously you can take it too far, but it’s an important skills for keeping the game moving. Like, say one character is obviously falling for some sort of trap by a doppelganger. OOC you either know or are suspicious, but IC you don’t. You want to go with them so they aren’t alone. But you can’t just say that. Say something like, “I’ll tag along, I’m getting stir crazy and could go for a walk.” It’s technically metagaming but it’s a very different situation than doing something like telling that character not to go because the other person is suspicious when you genuinely have no reason to think they are.

Another good example of metagaming that so many people view as okay that they don’t even view it as metagaming is telling your party OOC how many hit points you have remaining the healer choosing who to heal and with what spells based on the information. Your character doesn’t know that number. A lot of times all you really know IC is if someone has less than half of their hit points remaining and a vague idea that barbarians can take more hits than wizards.

Obviously there are scenarios where this doesn’t hold but I find in general that metagaming which benefits everyone, doesn’t completely ruin encounters, and is done with an excuse that your character would actually reasonably do is typically okay.

Another example. I remember in one game we were trying to open a creaky rusty door quietly. Someone asked if anyone had oil. We all checked our inventory and nobody did. He explained that my character in heavy armor would likely have some because regular maintenance of it would require that. Which seemed fine. The DM agreed. So my character hands his character some oil.

Eh, I know nothing about how to handle most dangerous animals, even ones that live in my area; I’d imagine that even in a world with trolls, regular people wouldn’t know anything about them.

If your character is a seasoned adventurer or monster enthusiast, sure, light it up, but if your backstory places you as the village baker for most of your life, running in with alchemist’s fire at the ready seems a bit strange.

Ultimately I’d consider it to be on the GM’s shoulders - if the only way your group is going to survive the troll encounter is with fire, then put an NPC in the local tavern who warms newcomers of a troll in the area, recommending that they have a lit torch at the ready.

It’s funny. I know a lot of players who think like you, but I and many others go in the completely opposite direction. The tension in my combat encounters has increased significantly since my group and I started to only give vague health info. Suddenly, it’s a surprise agin when a character goes down and you can almost feel the tension every round when another hidden death save is rolled!

I played all of Death Stranding 2 with BOOBA written on my back because I thought it was funny.

obligatory pathfinder fixes that

pf2e has an action called recall knowledge that lets you roll to see if your character knows something about something. in this case, player could ask if trolls have any weaknesses, and roll a recall knowledge check using society (trolls are humanoid) and they might be able to learn about the trolls’ fire weakness

Combat damage is random and it’s still dramatic and exciting knowing everyone’s health. I think hiding death saves is better than hiding health though. Because in reality everyone would act super urgently seeing a friend collapse. When I’m DMing I explicitly say when things are bloodied (less than ½) and double bloodied (less than ¼) in addition to qualitative explanations.

I think there are numbers worth hiding, I just don’t think character health is one. Like I think stealth rolls should be hidden. You shouldn’t have an idea that you’re not hiding well.

Counterpoint, fire was historically used to drive away predators and is commonly depicted in movies as well. A random townsfolk may not know all the particulars, but put fire between the bad thing and yourself is a reasonable strategy for most monsters. It becomes a metagaming problem if it’s only done against monsters that don’t resist fire.

Plenty of systems have something for that, often with a variety of options.

A bookish Exalted character might roll Intelligence + Lore to remember having learned about the weakness to fire before. Or maybe Intelligence + Occult if the weakness is supernatural in nature. A combat-oriented character might roll Wits + War to deduce that fire is needed based on the knowledge of old battle reports involving trolls. Maybe even something involving Survival if they’re familiar with a region trolls can appear in.

A game with a flexible skill system has a lot of room for such things.

Oh, sure, you could absolutely make a case for your character accidentally stumbling on the right answer simply because fire is a good weapon, and a good roleplayer could use that to their advantage to metagame a bit more acceptably, but there’s a difference between that and just automatically grabbing fire stuff because you the player know it’s good against trolls.

Plenty of systems have something for that, often with a variety of options.

I believe 5e has a similar rule, but it seems rare for players to have actually read the rules. I don’t think D&D is especially detailed about this, but I don’t know where the book is to check. I don’t think they give DCs, where I wouldn’t be surprised if Pathfinder 2e had a simple “target number is 8 + the creature’s HD” formula with guidance on what to do for the range of possible outcomes.

Like I think stealth rolls should be hidden. You shouldn’t have an idea that you’re not hiding well.

I don’t have the players actually make the stealth roll until something opposes it. They’re doing the best they can. Here comes the guard. Roll, please.

I’ll take a meta gamer over someone with “my guy” syndrome any day. At least they’ll progress the plot.

My guy syndrome?

Iirc it’s a level DC based off of the monsters level