In the finished novel, I've got one POV character, four main or major secondary characters (the line between those gets pretty blurry), and... eight? no, ten, I think, minor characters who get names. There are some other warm bodies wandering about. Oh, and some names that are mentioned in briefing reports and such, that we never meet. In the current WIP, there's three main characters and one major secondary so far, several very minor ones (mostly unnamed) that may or may not turn out to be more significant later, and one who's extremely important to the plot but actually has very little screen-time.
Lord knows what the NaNo project's count is going to be; I'm pantsing that one much more than I usually do.
Aimée wrote:that's my general guideline: if a character appears only once, there is no need to give them a name unless it serves a distinctive purpose, but if a character reccurs, even if only in one other scene, it's important that they have a name so the reader can
keep track of them.
Seconded. If a character's a one-off, why distract the reader with a name they'll never need to know again? It saves me having to make up more names, too.
Though I have had to go back and name a minor character when it turned out he'd be useful again in a later scene. (It's like recycling!)
As for last names, if they're major characters I usually give them full first & last names; the less time I spend with a character, the more likely they are to get only one name (first or last, depending on context), unless giving them more will tell the reader something useful about them. Most of my SF still deals with Earth-originated cultures, so the same rules apply; for aliens, it depends on the world-building behind them, and the levels of interaction I'm going to show. (Would they be called one thing by their CO, and another by their best friend? If so, they need two names.)