Albertson and Simpson in the Dungeon
This episode marks the first appearance of Picard's grey tunic and suede jacket uniform, which is absolutely bitchin' and didn't appear anywhere near enough. My love for it may or may not be tied into the uniform of the HARD Corps from Valiant comics.
Blink and you'll miss her, but this is Ashley Judd's first appearance as Ensign Robin Lefler. She would, of course go on to play a prominent role 4 episodes later in The Game. The character would reappear later in Peter David's New Frontiers novel series as a member of USS Excalibur's command staff. The script called for a character named Lieutenant Larson in the role, but it was altered by the time shooting started.
Also in firsts, this episode sees the first appearance of the Type 6 shuttlecraft, and Data's redesigned quarters. The old set was used for Kirk and Spock's quarters in Star Trek VI and was demolished after filming completed.
The exterior scenes were shot in Bronson Canyon in Griffith Park, a common location for on-site filming. It was used twice during TOS, again during Star Trek VI, three times more for TNG (Ensign Ro's exterior scenes were shot there only a few days later), and once during Voyager.
The Tamarian ship model was a significant modification of a Talarian ship first seen in the TNG episode Suddenly Human, and again as a Kriosian ship in The Perfect Mate. Between the latter episode and Darmok the model's dorsal and ventral fins were removed in favour of the side-mounted nacelles with paired spars linking them to the main hull, and wings on the outside of the nacelles. the model would appear twice in DS9 and twice in Voyager, picking up further modifications between each appearance but none so drastic as those preceding Darmok.
The episode was originally pitched by Philip LaZebnik, who also wrote the story and teleplay for Devil's Due and the teleplay for the DS9 episode Fascination.
The episode's teleplay was by Joe Menosky, who also has a co-writer's credit for the screenplay with LaZebnik. He joined the TNG staff in series 4 as a script editor, ultimately writing or co-writing 16 scripts for TNG, 4 for DS9, and 36 for Voyager. He's currently a writer and producer on Star Trek: Discovery.
The episode took 2 years to get to the screen, the longest gestation period for any episode during Michael Piller's tenure as showrunner. Rick Berman was reluctant to greenlight the story, but Piller believed in it, and assigned the script to Menosky to get into a workable version.
LaZebnik's story focused on the communication failure between the Enterprise and the Tamarians, but favoured a hive mind approach. Menosky came up with the idea of the Tamarians talking through metaphor.
Picard and Dathon's fight with the creature is in itself a metaphor for the story of Gilgamesh and Enkidu - they come together in conflict, fight a common enemy, one dies and the other mourns his death. The Epic of Gilgamesh is one of the earliest known examples of human literature, roughly four thousand years old.
Unsurprisingly, this episode is widely acclaimed. Michael Piller described it as the prototype of what Trek should be; Rick Berman, despite his reticence to approve the script cited the episode as one of his all-time favourites; Patrick Stewart said that if any TNG episode was to win awards, it should be Darmok; and while Winrich Kolbe said he found it difficult to direct the scenes solely in the Tamarian language, he loved the story and how it handled the result; Russell T. Davies even cited it as a favourite episode, one he wanted to "think about forever", he also cited it as an influence on the Doctor Who episode Midnight.
And in perhaps the ultimate accolade, it's been used by linguistics professors to teach how languages change and evolve.
As @Simonjones noted, Paul Winfield, who played Captain Dathon here also played Captain Terrell of USS Reliant in Star Trek II. The Irish comedian Ed Byrne has a great routine about meeting him in an airport:
Sherman, his eyes aglow
I've got two words for this episode: Science fucking Fiction. This is one of the best high concept episodes of Trek, easily top 10 TNG episodes, a strong contender for top 10 of all Trek. It's fantastic. And yeah, the idea of a language steeped solely in metaphor is less than realistic, but that's not really important. It's about the idea that we can speak the same language, but still be unable to communicate, and that's amazingly powerful. Compare it to stuff like Nasdat in A Clockwork Orange or the Belter Creole in The Expanse, where the normal process of taking words from other languages is accelerated and makes the language unintelligible even though the information flow is pretty much the same.
The idea of trying to communicate with an alien who doesn't think the same way you do is, of course a staple of literary SF, it's the core premise of Arthur C. Clarke's Odyssey trilogy, for example, or Peter Watts' Blindsight (my favourite recent SF book in the subgenre, that link is a legal free download!). Of course, Darmok can't take time to deeply explore the concept the same way a novel does, but it does incredibly well for a 45-minute run time, especially when they have Picard and Data and Troi discover how the Tamarians communicate independent of each other. I felt Data and Troi's scene where they're researching the language is a bit slow in retrospect, it takes them a long time to think to correlate nouns. But that might just be because I know the story, and I just want them to get on with it?
Even though there's a bit for everyone to do in the episode (even though most of Worf's part is to be told he's wrong again), the real show here is Patrick Stewart and Paul Winfield vs an alien costume so shitty, it could only be shot with optical filters in place. But the crappy monster isn't important, it's the moments of tension where Dathon is desperately trying to get Picard to understand "Temba, his arms wide". Picard's frustration when the Enterprise tries to beam him out is palpable,and you really feel for the two captains.
On a scale of 1 to 10, where 1 is Shaka, when the walls fell and 10 is Temba at rest? I give this one a solid Sokath, his eyes uncovered.