Let us talk about internal consistency in writing science fiction or fantasy. One of the more egregious mistakes I see in science fiction television and movies is a lack of consistency, which is why, to me, Star Trek the Next Generation does not hold up nearly as well as Babylon 5. Also, by not maintaining consistency on such things as alien natures and historical events in your writing, you miss out on spontaneous ah-ha moments that can make memorable scenes.
One of the things that kept me away from re-watching Star Trek the Next Generation and some of the following series (except for Enterprise, which many fans panned) was the episodic nature of the shows. For the most part, each episode was like a stand-alone movie that did not necessarily depend on anything that had gone before. Yes, there were a few things they would remember from earlier episodes and would from time to time give a nod to or reference, but for the most part it was as if the slate had been wiped clean after each show. The strongest episodes to me were the ones where they came back and explored aspects of earlier episodes from another angle. Examples of that are when they spent time exploring the aftermath of Picard’s capture by the Borg while the Enterprise was being repaired and Tasha Yar’s Romulan daughter from the episode “Yesterday’s Enterprise”.
Babylon 5; however, spent a lot of time on consistency, mainly because it was a fully planned story from season one to season five. Yes, there were a lot of changes during the course of the series, but the overall plan helped to minimize the problems. I believe that they even had plans set up to cover situations like losing a lead actor. What is more important is that aspects of character’s personalities, species histories and natures, and episode histories were kept consistent. Unlike STNG where characters who were portrayed one way in an episode suddenly are portrayed another way just for the sake of the episode. I don’t mean to jump too hard on STNG because at the time I did enjoy many of them, but as the series and then DS9/Voyager continued, I saw a phenomenon that really turned me off. To me it seemed that major characters would fall deeply in love with a different character every few episodes. It felt like the producers were watching the internet, checking to see who fans felt show be couples.
Look at the Worf, Riker, and Deanna relationship. First it was Riker and Deanna while Worf loved a Klingon, having a child with her before she died. Riker and Deanna moved on and Worf moved into a deep relationship with Deanna. Then when Worf moves on to DS9, Deanna is just gone and he ends up marrying Jadzia Dax. Just because you may not be able to get the former actor for a role doesn’t mean you should just drop the history you created. For example, look at how J. M. Straczynski handled the loss of Richard Biggs and Andreas Katsulas in Babylon 5: The Lost Tales. When asked about G’Kar, President Sheridan says “He is off exploring beyond the rim” and is later told that Dr. Franklin has gone with him, handled simply with a line that fits the characters without changing or warping other characters to fit into some new reality. Also, in the final episode “Sleeping in the Light”, Garibaldi, Sheridan, and Franklin shared a funny story about a Pak’ma’ra that takes advantage of the species traits established much earlier in the series.
Another good example, so far, of consistency comes from Brandon Sanderson’s Mist Born books. In creating the world, he set down very specific rules for the system of magic used by the people. In some ways this codification of magic rules could have tied down what characters could do, but Sanderson found ways in later books to accomplish new actions using the same rules instead of ignoring them to write the scene he wanted. In other words, he allowed the limitations of the world he created to define how he wrote the scenes. Another example of attention to details comes from “The Lord of the Rings” and “The Hobbit” movies directed by Peter Jackson. Just watch the extras to see how much time was spent catching continuity errors.
Consistency can have a strong effect on people who watch movies or read books a lot, possibly damaging their opinions over time by confusing them or forcing them to make rationalizations for errors. Star Trek and Star Wars are ripe with those. I find myself cringing every time someone says how good Rogue One was because I want to say “but did you see…” So, while I still mostly enjoy many commercial science fiction and fantasy offerings, even when consistency is an issue, I find myself irritated more as I grow older. I even choose to forgo some offerings because I just don’t want a good memory tarnished by sub-par efforts, even from the original creator.