I'll come right out and say it: Star Wars has a badly-designed universe; so poorly-designed, in fact, that one can say that a significant goal of all those Star Wars novels is to rationalize and mitigate the bad design choices of the movies. Need examples? Here's ten.
R2-D2
Sure, he's cute, but the flaws in his design are obvious the first time he approaches anything but the shallowest of stairs. Also: He has jets, a periscope, a taser and oil canisters to make enforcer droids fall about in slapsticky fashion -- and no voice synthesizer. Imagine that design conversation: "Yes, we can afford slapstick oil and tasers, but we'll never get a 30-cent voice chip past accounting. That's just madness."
C-3PO
Can't fully extend his arms; has a bunch of exposed wiring in his abs; walks and runs as if he has the droid equivalent of arthritis. And you say, well, he was put together by an eight-year-old. Yes, but a trip to the nearest Radio Shack would fix that. Also, I'm still waiting to hear the rationale for making a protocol droid a shrieking coward, aside from George Lucas rummaging through a box of offensive stereotypes (which he'd later return to while building Jar-Jar Binks) and picking out the "mincing gay man" module.
Lightsabers
Yes, I know, I want one too. But I tell you what: I want one with a hand guard. Otherwise every lightsaber battle would consist of sabers clashing and then their owners sliding as quickly as possible down the shaft to lop off their opponent's fingers. You say: Lightsabers can slice through anything but another lightsaber, so what are you going to make a hand guard out of? I say: Dude, if you have the technology to make a lightsaber, you have the technology to make a light hand guard.
Blasters
A tactical nightmare: They're incredibly loud, especially for firing what are essentially light beams. The fire ordnance is so slow it can be dodged, and it comes out as a streak of light that reveals your position to your enemies. Let's not even go near the idea of light beams being slow enough to dodge; that's just something you have let go of, or risk insanity.
Landspeeders and other flying vehicles
Here's the thing: In the Star Wars universe, there are no seatbelts. And maybe if you're flying your hoity-toity vehicle on Coruscant, you have, like, a force field that keeps you flying out of your seat. But Luke's X-34 speeder on Tatooine? The Yugo of speeders, man. One hard stop, and out you go.
Stormtrooper Uniforms
They stand out like a sore thumb in every environment but snow, the helmets restrict view ("I can't see a thing in this helmet!" -- Luke Skywalker), and the armor is penetrable by single shots from blasters. Add it all up and you have to wonder why stormtroopers don't just walk around naked, save for blinders and flip-flops.
Death Star
An unshielded exhaust port leading directly to the central reactor? Really? And when you rebuild it, your solution to this problem is four paths into the central core so large that you can literally fly a spaceship through them? Brilliant. Note to the Emperor: Someone on your Death Star design staff is in the pay of Rebel forces. Oh, right, you can't get the memo because someone threw you down a huge exposed shaft in your Death Star throne room.
Bad design in Star Wars is not just limited to stuff; evolution here seems wacky, too. Three choice bits:
Sarlaac
A monstrous yet immobile creature who lives in an exposed pit in the middle of a lifeless desert, waiting for large animals to apparently feel suicidal and trek out to throw themselves in? Yeah, not so much. Not every Sarlaac can count on an intergalactic mob boss to feed it tidbits.
That Asteroid Worm Thing in Empire Strikes Back
So, large space worm lives in asteroid, disguises itself as a cave and waits for unwary spaceships to fly by so it can eat them? Makes the Sarlaac look like a marvel of natural selection, it does.
Midi-Chlorians
Oh, man, don't get me started. Except to say this: If in fact a high concentration of midi-chlorians is the difference between being a common schmoe and being a dude who can Force Choke his enemies, the black market in midi-chlorian injections must be amazing.
Winner of the Hugo Award and the John W. Campbell Award for Best New Writer, John Scalzi is the author of The Rough Guide to Sci-Fi Movies and the novels Old Man's War and Zoe's Tale. He's also Creative Consultant for the upcoming Stargate: Universe television series.