This is a very specific rule that has been taken dramatically out of context and is almost always used incorrectly.
“Show, don’t tell” applies to character traits and worldbuilding, not information in the plot.
It may be easier to “get” this rule if you forget the specific phrasing for a minute. This is a mnemonic device to avoid Informed Attributes, nothing more and nothing less.
Character traits like a character being funny, smart, kind, annoying, badass, etc, should be established by their behavior in-universe and the reactions of others to them–if you just SAY they’re X thing but never show it, then you’re just telling the audience these things. Similarly you can’t just tell the audience that a setting has brutal winters and expect to be believed, when the clothing, architecture, preparations, etc shown as common in that setting do not match those that brutal winters would necessitate.
Violations of Show Don’t Tell:
A viewpoint character describing themselves as having a trait (being a loner, easily distractable, clumsy, etc) but not actually shown to possess it (lacking friends, getting distracted from anything important, or dropping/tripping over things at inopportune moments.)
The narration declaring an emotional state (”Character A was furious”) rather than demonstrating the emotion through dialogue or depicting it onscreen.
A fourth-wall-breaking narrator; ie, Kuzco in The Emperor’s New Groove directly addressing the audience to explain that he’s a llama and also the protagonist, is NOT the same! This actually serves as a flawless example of showing rather than telling–we are SHOWN that Kuzco is immature and egotistical, even though that’s not what he’s saying.
A fictional society or setting being declared by the narrative to be free of a negative trait–bigotry, for example–but that negative trait being clearly present, where this discrepancy is not narratively engaged with.
(For example: There is officially no sexism in Thedas and yet female characters are subject to gendered slurs and expectations; the world of Honor Harrington is supposedly societally opposed to eugenics, yet “cures” for disability and constant mentions of a nebulous genetic “advantage” from certain characters’ ancestry are regular plot points that are viewed positively by the characters and are not narratively questioned.)
A character declaring that their society has no bigotry, when that character is clearly wrong, is not the same thing.
The narrative voice declaring objective correctness; everyone who agrees with the protagonist is portrayed as correct and anyone who questions them is portrayed as evil, or else there is no questioning whatsoever. For example: in Star Trek: Enterprise, Jonathan Archer tortures an unarmed prisoner. What follows is a multi-episode arc in which every person he respects along with Starfleet Command goes out of their way to dismiss the idea that he should bear any guilt, or that his actions were anything but completely necessary and objectively morally correct. No narrative space is allowed for disagreement, or for the audience to come to its own conclusion.
NOT Violations of Show Don’t Tell:
A character explaining a concept to another character who would logically, within that universe/situation, be the recipient of such an explanation.
An in-universe explanation BECOMES a SdT violation if the explanation fails to play out in reality, such as a spaceship being described as slow or flawed in some way but never actually having those weaknesses. Imagine if the Millennium Falcon was constantly described as a broken-down piece of junk…and never had any mechanical failures, AND Han and Chewie weren’t constantly shown repairing it!
Information being revealed through dialogue, period. Having your hacker in a heist movie describe the enemy security system isn’t “telling” and thus bad writing. Having information revealed organically through dialogue is what “show” means.
The “as you know” trope is technically a Show Don’t Tell violation, despite being dialogue, because it’s unnatural within the universe and serves solely to let the writer deliver information directly, ie, telling.
Characters discussing their own actions and expressing their motivations and/or decision-making process at the time.
The existence of an omnipotent narrator, or the narration itself confirming something. Narration saying “there was no way anyone could make it in time” is delivering contextual information, not breaking Show Don’t Tell.
Keep in mind that “Show, don’t tell” is meant to be advice for beginning authors. Because “telling” is easier and requires less skill than “showing,” inexperienced authors need to focus on getting as much “show” in as possible.
However, “telling” is also extremely important. Sometimes, especially in written formats, the most appropriate way to deliver information to the audience is to just say it and move on.
Keep in mind that a viewpoint character in anything but…a portal fantasy, essentially…is going to be familiar with the world they’re in. Not every protagonist needs to be a raw newcomer with zero knowledge of their new world! In most cases, a viewpoint character is going to know things that the audience doesn’t. Generally, the ONLY natural way to introduce worldbuilding in this situation is to just have the narration point them out. (It makes sense for Obi-Wan to have to explain the Force; it would make no sense for Han to explain the concept of space travel to Luke, who grew up in this universe and knows what the hell a starship is. So, if you’re writing the novelization of A New Hope, you need to just say “and so they jumped into hyperspace, the strange blue-white plane that allowed faster-than-light travel” and move the hell on.)
For that matter, in some media (ie, children’s cartoons) where teaching a moral lesson is the clear intent, a certain level of “telling” is not only appropriate but necessary!
The actual goal of “showing” and “telling” is to maintain a balance, and make sure everything feels natural. Show things that need to be shown, and…don’t waste everyone’s time showing things that would feel much more natural if they were just told.
But that’s not nearly as pithy a slogan.
