If I had a gold piece for every time a game has been derailed because two players stop to discuss whether they're guilty of accidental "metagaming", I'd be a as wealthy as a brass dragon (not that brass dragons are any richer than any other dragon, necessarily, but they are my favourite dragon). Metagaming, of course, is the modern term generally used to indicate when a player has their character perform some action in the game based on knowledge that the character could not possibly possess. People often frown upon this, and sometimes take the definition of metagaming to the extreme. But I don't mind metagaming, and I don't think people should worry about it in their games either, and this post is going to explain why.
First, a quick caveat. I am aware that some players just don't understand that fun is meant to be evenly distributed, and use metagaming as a way to "win" what becomes, essentially, their own private D&D session with everyone else playing as their forced audience. Those people aren't fun to play with, and they ruin game sessions, gaming groups, and discourage new players from turning into regular players. This post is not intended to empower people who cheat, bully, or otherwise make gaming a not-fun experience. Furthermore, the problem in those cases is not metagaming. The problem in such cases is that a person doesn't understand how to treat other people with respect. Debating whether they're metagaming when they just happen to know exactly where the all the best loot in the module is located, and knows all the plot points well in advance, is not going to fix the issue. That issue is the topic for a different kind of post. This is not a post about problem players. This is about metagaming, and why I allow it when I DM.
One problem with calling out a player (yourself included) for metagaming is that nobody seems to be able to agree on what qualifies as metagaming. Take this example scenario: a rogue breaks away from the party to investigate a secret door. While separated from the party, the rogue is attacked by a zombie, but luckily her fellow players hurry to her rescue, even though there's no way they could have known she was being attacked. The only reason the characters rushed to help is because the players heard the DM and the rogue player enter combat. That's inarguably metagaming (although, for the record, I wouldn't disallow it at my table, and I'll tell you why later). By many people's ruling, it's flat-out cheating. Regardless of how you feel about it, it's a good upper limit for a definition of metagaming.
Anything less severe than that example, though, are harder to classify. I've witnessed debates about whether it's metagaming to not cast True Polymorph on a Flesh Golem, because while the player knows that many golems are immune to such spells, the character shouldn't know that. Another example is the Insight [5e] or Sense Motive [3.5] or Perception roll: the theory is that a player should not know the results of their roll for fear that, should they roll low, they'll understand that, whatever the DM says in response, the opposite is probably true. There are arguments about metagaming that splits hairs even finer than these examples, and they inevitably slow the game down, distract the players and the DM, and generally turns game night into a panel discussion of the philosophy of virtualized realities.
Representatives from the D&D development team say "When in doubt, read the text". Interestingly, the Player's Handbook has no text about metagaming. The Dungeon Master's Guide has two paragraphs about it. The ruling in the DMG is: "Discourage metagame thinking by [asking] players what [their] characters think. You can curb metagame thinking by setting up situations that will be difficult for the characters and that might require negotiation or retreat to survive."
Based on that, I believe:
Metagaming isn't seen as a serious game-breaking bug by Wizards of the Coast.
Like everyone else in the world, Wizards doesn't have a solid definition for metagaming.
I agree with the advice provided in the DMG, although I find it vague without more context. Their advice mirrors my own method for handling metagaming as both a DM and a person with a character, so this blog post may serve to expand upon the DMG's advice, at least the way I interpret it.
D&D is a good game. It's a robust system with lots of variables handled with great alacrity. D&D players know this, and have known it for decades. The fact is that D&D is a robust and resilient game that cannot be broken by metagaming. I believe Wizards of the Coast knows particularly well, and so didn't bother belabouring the point in the DMG (or even mention it at all in the PHB).
If metagaming were truly a plague upon RPGs, then no RPG would be playable after a year or two. Players learn details about monsters, they learn about the common tropes in dungeon and world design, they hear "spoilers" about popular published modules, and so on. And, besides, even a new player could potentially be accused of metagaming the first time they encounter, for instance, an undead creature and intuitively cast Healing in hopes that it would have the opposite effect, bizarro-world style. Or the first time they encounter a Medusa and intentionally do not meet her gaze. Or the first time they encounter Strahd and reach for holy water, and so on. D&D cannot be that fragile. If it were spoilt by player knowledge, then it would be failing at being a game.
D&D has accounted for metagaming long before "metagame" was a term. The designers intuitively understood that players were not their characters, and that gamers, by their very nature, tend to love to game the system. So the system was designed to game back.
First of all, there's the DM. The DM is the first line of defense against effective metagaming, as the DMG itself indicates. If players are metagaming, the DM can foil their plans by simply making changes to whatever it is that players think they know. Are the characters rushing to help a party member they can't possibly know is in peril? A good table of dungeon traps can make them regret that decision. Is a player using knowledge about a monster to gain an unfair advantage in a fight? A quick change of the monster's skills or attacks ought to restore balance, or else some surprise added features (difficult terrain, minions, surprise immunities, and so on). The CR of an encounter is adjustable, the dungeon is malleable, and the DM has ultimate control over the module.
The possibilities are endless, and it's the system's job to ensure all the math works, and the DM's job to ensure that the scenario is fresh no matter what is overheard at the table, or read in between sessions, or has just become common knowledge from general reputation.
Remember, one of the best selling AD&D module franchises was Dragonlance, which had players moving through the stories of Dragonlance novels that they could also pick up from their local book store and read. Imagine if Game of Thrones had encouraged viewers to go and buy the books during a season. That's exactly what Dragonlance did, and it worked. People read the novels, played the novels, bought the source books, and nothing (aside from Fizban, maybe) was sacrificed.
Modern D&D has a significant emphasis on story. Of course, D&D has always been rich in lore, but game play spans a spectrum between story and hack-n-slash dungeon delve. For people interested in the sanctity of the story, metagaming is less about cheating as it is about disruption of the narrative flow.
But in a way, metagaming is actually part of the improvised storytelling process because metagaming is almost always as easily explained as it is debated. When a character responds to something beyond their awareness, maybe they simply had a strange intuition that something was amiss. If it happens often, then maybe a god or extra-planar being is attempting to contact them, with a side-effect being divine or extrasensory awareness. If the effort to contact them continues unanswered, this being (friendly or otherwise) might even decide to pay them a visit. When a character seems to be acting on information straight out of the Monster Manual or the module, then maybe the character has heard legends about the creature or place they are faced with. If it happens often, maybe the character is reliving an experience from their own past. Maybe they are re-living their life, and isn't it peculiar when things start happening different than the last time they [uncannily] experienced it?
Instead of debating the metagame, you can embrace it. You can turn it into a storytelling opportunity by asking how, in the story, the metagamed event happened. Instead of demanding a retraction of some action, ask for and encourage story-based answers, and then develop the answer further in character. In other words, it's metagaming for a player to ask another player why they're metagaming, but it's part of the story if a character asks another character how they have leapt to a seemingly random, unfounded conclusion.
I DM as often as I delve, so I know all too well just how much a DM has to do during a gaming session. While I don't want to add to the list of DM responsibilities, the DMG makes it pretty clear that curbing metagaming is up to the DM and not the players (remember, the PHB has 0 mentions of metagaming). The good news is that it's not really something a DM has to think about. You know when someone is metagaming, because they are using information their character simply doesn't have. In the rare cases that it's an actual problem, use DM fiat to make it ineffective. That secret passage that a player inexplicably is convinced exists because they spent their weekend reading the module at home? It's moved to a different location, or maybe even a different plane. The villain's lair a player wants to rush into, even though the character does't know who the villain is yet? There are consequences for knocking down doors without a warrant. And so on.
Play the game. D&D is a role-playing game, and its intent is for you to play your character. If you think you might be metagaming, pause and imagine the game as a video game. Would your character in a video game RPM have the option to take the action you're about to take? If not, then you may be gaming the real-life flexibility of tabletop RPG. If you think that may be the case, either don't do the thing you were about to do, or else announce your suspicion and let your friends help you work through it. As demonstrated, most metagaming can be explained by a better story, and it can be absorbed by what is a resilient gaming system.
As we say in the entertainment business (and D&D is, after all, entertainment): the show must go on.
Don't let metagaming stop it.