(Warning: Copious amounts of bad language follows, for those whose eyes bleed easily.)
I'm writing a story where the protagonist is a rock guitarist, and naturally enough, one of his favorite words is "fuck." This got me to thinking about cursing in general, both in the real world and in the pages and on the TV screens of our favorite SFF universes.
One of my favorite examples of the latter is Battlestar Galactica's (reboot version) "frak." (The word has been somewhat co-opted in the real world by the method of drilling for natural gas known as hydraulic fracturing, shortened to "fracking" in the media. Note that I spell BSG's cuss word differently, both to differentiate and because of the fact that "frakking" just looks cooler; the c seems to drag the word down.) BSG's creator Ron Moore obviously used the word as his universe's equivalent to our "fuck," as a way to get in appropriate amounts of military-style cussing without being censored. In spite of the fact that the word got a bit overused in the show's final season (especially when President Laura Roslin said to someone, "You don't know frak"--ugh. That sentence bounced off my astonished skull and fell to the floor in an ungrammatical, suspension-of-disbelief-shattering heap), I'm still quite fond of it.
In the original 70's Battlestar, there were a couple of other invented words. Anybody remember "felgercarb?" As I recall, it was the Colonies' version of "bullshit," although they obviously couldn't--and fortunately, never tried to--twist it into the real-world version of "you're shitting me." You're carbing me, anyone? There was also a little thing called a "centon," which, according to however it was used in a sentence, seemed to be a measurement of both space and time. This led to a memorable moment (for me, anyway) when that week's guest star--if I remember correctly, it was Emergency's Randolph Mantooth, playing a suspiciously human-looking alien recently awakened from a cryogenic sleep--stopped in the middle of a rather tense scene to confront one of the show's stars, his voice boiling with frustration: "Apollo. What is a centon?"
In a particularly ham-fisted bit of editing, the scene cut off right there, so neither Mr. Mantooth nor the show's audience ever got an answer.
I've never watched Farscape, but I've heard it has several invented curse words. The one I've heard most often is "frelling," which I have to say I do not like. To me, it slides out of one's mouth like a dead snake, falls splat on the floor, and just lies there. In contrast, "frak" explodes out of your mouth like an angry bird and wings viciously off to do its damage. Obviously the difference is the final consonant; the authoritative, nasty k is just so much more satisfying than the slippery, weak l.
However, all of these words can be taken too far, as has happened to our real-world favorite, "fuck." It has, unfortunately, been demonstrated that this one word can be used as an adjective, a noun and verb, to wit: "This fucking fucker's fucked." I suppose this would appeal to those who insist that real people do say things like this, to which I would be tempted to reply, "Yes, and real people can be awful goddamn boring. You can't write a book about boring people." (Well, I guess you could write lots of books about boring people, if you like filling up trunks.) There's being simple and smart, a la Hemingway, and there's being repetitive and stupid, a la using the same curse word every other sentence. Which is why I've taken pains to have my rock star use his favorite word, in either dialogue or description, only once per page, if at all. There's plenty of other delightful British euphemisms I can substitute, like "bloody" and "shag" and "sod."
For that matter, there are plenty of ways to insult people without using curse words at all; apparently Shakespeare was a master of this. There are also lots of old-time, backwoods American expressions that do the same thing. "He's as useless as teats on a boar hog," and "you talk like you fell out of a well," are two of my favorites. (I collect phrases like that; I have a book of them, to which I've added others I heard from my parents, aunts and uncles. They would rarely say anything stronger than "darn" or "heck," but they could dismiss someone with a scathing, "He doesn't know his rear end from a hole in the ground.")
But as colorful as these phrases might be, they obviously can't be used by everybody. (And who was the author who came up with "tanj," which I believe was the acronym for "there ain't no justice?" Ouch. That's even worse than "frell." Talk about schoolboys with weak, receding chins.) I don't think cursing necessarily indicates--for either author or character--stupidity or a lack of education (sexist curse words like "bitch" and "cunt" are in a different category, which I'm not tackling at the moment), but as with all things, you can quickly overuse it.
After all, you can say "fuck/frak you" or you can say, "Go play on the freeway." The richness of our language, and the inventiveness of our storytellers, allows for both.