I was wondering, there's something that keeps me asking myself in Star Wars and other SF universes.

Many S-F universe use "vintage" or "crappy" or "old-fashioned" designs for robots. Like C3PO & R2 units in Star Wars or Fallout or even in the Asimov's Cycle of Robots. Non-humanoid robots are described or look like big rolling trash bins.

Is there a reason why we could think it'll be like this ? Is there any rational reason (like economic reason ? Development of recycling ?)

  • 31
    $\begingroup$ It was a long long time ago... $\endgroup$ – Rory Alsop Jan 5 '17 at 15:34
  • 12
    $\begingroup$ ... and they're in a different galaxy, far, far away... $\endgroup$ – user10945 Jan 5 '17 at 15:37
  • 13
    $\begingroup$ Why would you have "droids" - short for android, a human-like machine - in factories? If you were sensible, you'd do just what is done today: design your factory robots to perform their tasks efficiently. $\endgroup$ – jamesqf Jan 5 '17 at 19:18
  • 1
    $\begingroup$ It's somewhat difficult to answer this without knowing what specific features you're talking about. What makes the design of, e.g. R2-D2, crappy? What would you change in a droid designed for the same task? $\endgroup$ – Ray Jan 6 '17 at 4:40
  • 2
    $\begingroup$ Even star wars doesn't use R2-D2 like droids for "factory" use. Look at the factories in Ep 3, those are more like modern automated factories, there aren't (that I recall) R2 or humanoid droids standing at assembly lines as if they were humans. $\endgroup$ – Jason K Jan 6 '17 at 15:02

Three reasons:

  • They're characters
  • They're easy to make into toys
  • They're easy to make into props/models/fit actors into

If you ask this on the Sci-Fi & Fantasy community, you'll get a reasonable in-universe answer.

But the truth is, that they're just characters and robots being exactly fit for purpose would be relatively boring to watch/play with.

  • 3
    $\begingroup$ I think cost is a factor too. Some movies don't have the budget for CGI or advanced props so they make due with whatever they can. Sometimes, gluing a few pieces of metal and some eyes onto a garbage can is the cheapest and fastest option so that's what they do. $\endgroup$ – aleppke Jan 5 '17 at 20:18

Please bear in mind that I've only seen the movies - and not often at that - but I think they offer some good reasons for the design choices.


R2 was at some point in one of the original movies picked up by some kind of crane dealie (the technical term, I'm sure) and placed into the pack of Luke's x-wing. It seems like, for whatever reason, it was desirable to have a component of the plane that could leave the ship, take instructions, and be lifted into another ship.

With those requirements you could really make R2 any shape you like, but something very sturdy and unlikely to fall down seems like a good choice. Using limbs or treads would probably complicate the "installation" procedure.

R2D2, installed


C3PO was built by a child - no further design justification needed. Frankly C3PO's lucky he didn't end up looking like a toaster with wires sticking out of it for no good purpose, as my attempts did when I was younger.

His construction was actually criticized by others at the time, when in one of the newer movies he was told he was "naked" because he didn't have a proper outer shell yet. I assume he had one made later that fit the way his skeleton was put together.

  • 17
    $\begingroup$ C3PO was built by a child, but probably not designed by one. In the movies, we encounter other droids of the same design, so I think we can assume C3PO was assembled from scavenged parts. Being a protocol droid (specifically for "human-cyborg relations"), the humanoid shape but still mechanical appearance is likely a good design decision. Humans relying on C3PO to intermediate their interactions with other tech, would likely find him a good representative. $\endgroup$ – Adrian McCarthy Jan 5 '17 at 20:49
  • 1
    $\begingroup$ I think there's a bit with R2D2 doing this in The Phantom Menace - some astromech droids like R2D2 have the ability to roam around on the hull of ships to make repairs in vacuum, which means they need to be relatively small and sturdy in order to avoid being hit by laser shots or debris and handle the G-forces. He also seems to be able to make X-Wing repairs from inside his slot on the ship, so presumably they just designed the X-Wings to take advantage of the droids they already had for larger ships. $\endgroup$ – IllusiveBrian Jan 5 '17 at 21:55
  • $\begingroup$ @IllusiveBrian The prequel trilogy and clone wars series shows various other one-man fighters equipped with R2 droids, so your hypothesis that the X-wing was designed for taking R2 droids and not the other way around is quite plausible. $\endgroup$ – Philipp Jan 6 '17 at 9:20
  • 1
    $\begingroup$ In the EU (Legends), the X-wings don't have a hyperspace computer - they have the engines, but not the brain to make it happen. So they use standard astromech droids (like R2) to provide hyperspace calculations. Astromechs predated the X-wing design - and in the prequels, we see that they were actually used on large ships for various maintenance duties. Are they the best possible shape and form for that? No... but they had to fit an actor inside for the old trilogy :P $\endgroup$ – Luaan Jan 6 '17 at 11:10
  • $\begingroup$ +1 for the general idea; I think the C3PO part needs revision, given Adrian's comment which I wholeheartedly agree with. $\endgroup$ – Joe Jan 6 '17 at 16:11

Depends by what you mean by 'crappy'

Human form factors suck. Walkers are pretty darned inefficient.

Lets consider the trash bin form factor.

For example one of these

enter image description here

No actually, one of these

enter image description here

Your sensors can swivel 360 degrees

You have stability (since you have 3 points on the ground) on a smaller, more flexible setup than a 4 wheeler. Its uniquely suited to fit into a standard recepticle, which is compatible with other models like the R5 and BB series.

Of course, they also sometimes had to climb out, in the middle of a gunfight, and r2 got hit a few times. Oh, and did you know you could fit a little person inside one?

Lets consider a few more robot designs

the mouse droid or K9 from dr who.

Box with wheels. Cheap, simple. Completely baffled by stairs.

enter image description here

Also gets no respect.

enter image description here

Wall-e. Adorable little cannibal trash compactor. Designed for his environment, though those arms... are a little odd. He is though a good basic design for a mobile, sentient trash compactor. Practical threads. simple box design

In a sense though form follows function

On the other hand, I like my industrial robots like I like my prison furniture. Firmly bolted to the ground. I suppose you could put them on rails, or maybe wheels, but why does my industrial equipment need to walk off and bother the local wildlife?

There's a good reason modern robots are just arms

enter image description here

You have a basic range of motion similar to an arm but entirely suited to the task. Swappable functional ends. r2 is adorable. A robot arm on the back of your X wing could shoot back, swap its working end from a gun to a fire extinguisher and put out a fire. Then switch to a tool to pull out a dead engine, put in a spare, and throw the dead engine at a tie fighter. Assuming you had a spare engine. Or an r2 droid.


It's interesting that you ask this, I was just thinking of my Roomba and why it is now obvious why it is round. Wheel motion would be difficult if it was any other shape rather than round. I mean when the Roomba needs to navigate it goes forward, stops, spins in the new direction and then continues. If it had corners its programing would have to use the center to the farthest corner as the diameter of its spin circle.

The next reason is that we as human designers prefer things to look nice from our point of view. Therefore, cars in the 60s had fins and in the 40s were art-deco, etc. Each decade has its own type of design. When I see Star Wars, even Rogue One, I think, boy is that from the 70s!

My conclusion is that it is human nature that things are designed more to reflect aesthetics rather than function. A quick look at my desk shows me that. For example does my desk phone need to be that big? Does the handset need to have a lead weight in it? Do my monitors really need blue lights on the power button?

  • $\begingroup$ Monitors do need light on power button. In some jurisdictions it's mandatory for such devices to have power on indicator. $\endgroup$ – Mołot Jan 5 '17 at 16:25
  • $\begingroup$ Other than accidently, I have never powered off my monitor deliberately in 2 years, which is how old they are. I meant, why blue as oposed to white which is the light's natural color $\endgroup$ – Frank Cedeno Jan 5 '17 at 16:34
  • $\begingroup$ Oh ok. I've seen them blue, red, amber, white... Color is aesthetic choice. The fact they are is not :) $\endgroup$ – Mołot Jan 5 '17 at 16:40
  • 1
    $\begingroup$ Monitor lights are very useful. If the screen is black, is it because there's no power, or because there's no (or an all-black) signal being sent to the screen? If there were no light, we'd waste a lot of time turning our screen off and back on again, and still wondering. Just saying. :) $\endgroup$ – Brian Lacy Jan 5 '17 at 21:29
  • 1
    $\begingroup$ @FrankCedeno: White LEDs are made using blue ones: en.wikipedia.org/wiki/Light-emitting_diode#White $\endgroup$ – nzaman Jan 6 '17 at 6:48

In general the look of technology is inspired by real world things, either contemporary or historic, often designers will mix a number of elements to evoke the look and feel which is required for the production.

I actually think that the design aesthetic of the original trilogy has stood up pretty well. One reason for this is that they went for a fairly grimy and industrial look which, in the real world tends to be dictated by practicality rather than fashion and so it remains reasonably relatable.

With any form of design it is extremely difficult to come up with something which is totally original and innovative, especially at the sort of short notice required for film and TV design and entirely impossible to reliably guess what technology far in advance the current would really look like and sci-fi designers have, in the past got things remarkably right but also very wrong.

There is also a phenomenon in robot design known as the uncanny valley this is where artificial things which look a lot but not exactly like a person make people quiet uncomfortable. Which has led some robot designers to speculate that consumer robots in the future would be better looking like robots rather than attempting to mimic people, if only from a marketing and user interface perspective.

Looking at the star wars examples in question. R2D2 is apparently a versatile (some would say a bit too versatile for the sake of plot convenience) utilitarian robot whose main function seems to be the maintenance of other machines. In this context a short cylindrical body with small wheels and limited ability to 'walk' makes reasonable sense for something which is intended to mostly move around on flat surfaces and is exactly the sort of thing you would expect to see on a factory floor. Indeed a lot of real world mobile industrial equipment like diagnostic stations and welding equipment have a very similar form factor


Walkers are computationally expensive and relatively slow. Looking at the real life example of BigDog helps provide us with context.

BigDog was funded by the Defense Advanced Research Projects Agency (DARPA) in the hopes that it will be able to serve as a robotic pack mule to accompany soldiers in terrain too rough for conventional vehicles. Instead of wheels or treads, BigDog uses four legs for movement, allowing it to move across surfaces that would defeat wheels.

A robot with wheels may be more energy efficient, durable, and perhaps most importantly: fast. Because they require far less computing power they also can be much smaller. Robots who can zip about inside space ships and urban environments at high speed with wheels don't need to be particularly futuristic. They can afford to be a bit boxy, and perhaps more like a toy radio controlled monster truck with good suspension and ground clearance.

Another possibility is that someone devises antigravity. So they are capable of floating across obstacles, then returning to a wheeled mode for higher speed (assuming antigravity is energy intensive too). A robocheetah may be cool, but it's pretty much design overkill when you could have a comically fast miniature jawa sandcrawler instead to fetch mail/lunch/coffee.


well let's look at the droids. One is a mobile navigational computer/repair drone, which means you want it cheap (aka replaceable) and compact. and a little wheeled trash can is both, making it walk would be a lot of extra cost for no real gain.

The other is built to facilitate humanoid communication which means it has to be human shaped, but it was also built by a slave from spare parts so it's not exactly the most versatile of machines.

The combat droids are built to be both cheap as possible and exploit existing military infrastructure so a simplistic humanoid shape makes sense.

The all seem to make sense.


For the same reason almost all non-human characters in sci-fi and fantasy are bipedal and human-shaped - because that's the shape of the person inside the suit. The simplest limit in making a film is the question of how you make that thing move.

Ray Harryhausen and his colleagues were the first step in moving past those limitations. Harryhausen's skeleton army is still pretty damn amazing even today, when our standards of FX are considerably higher. Back in the day, it must have been mindblowing. Stop-motion is clearly the predecessor of modern CGI creatures, because it allows any creature to be animated which the creature can imagine, with no real physical limitations to the creature or to how it moves.

There were plenty of interesting side-quests via physical puppetry though. Jabba the Hutt, in RotJ, was a physical creation with several people operating it. Most amazingly, I strongly suggest you watch the director's cut of Aliens and how they filmed the Queen versus Powerlifter fight - yes, that is genuinely a 15-foot structure that Sigourney Weaver is standing in, and yes, that is genuinely a 15-foot fully-detailed alien, and yes, they are genuinely pacing round each other and lunging at each other. The director's cut has a significantly extended fight with several long cuts, which makes it even more mindblowing. Each one is basically operated by a team of weightlifters, but so skillfully operated and so well shot that it's utterly compelling.

As impressive as all this is though, essentially it's a dead end. If you want realistic non-humanoids, of any description including robotic, and there are compelling reasons for them to be actually non-humanoid, then anything involving a human is a non-starter. In that case CGI or good physical FX without a human inside (BB-8, for instance) are the way forward. In the original Terminator, the "hunter-killers" were tanks or aircraft, which completely made sense.

The Cylons (BSG) are an interesting counter-example though. They're CGI, but CGI of a humanoid robot. If they were simply a tracked weapons platform then they'd be much more effective as a weapons platform, but the plot requires them to be scary. Uncanny Valley makes something scary if it looks a bit like us but clearly is not like us. (And of course there's the 70s TV series, where the Cylons are just men in robot suits, which limits expectations.) So in spite of the physical possibility of making Cylons a devastating weapons platform of any shape they chose, narrative requirements mean they're just another humanoid.


Just think of R2-D2 as an intelligent rolling toolbox.

Say you were to design a robot to work in a mechanics shop you might go for a similar design.

You would want it as small as possible but large enough to carry all the tools and diagnostic equipment needed. Waist high or counter height seems about right, although I might put some type of flat surface on top instead of a round dome.

The round shape allows maximum internal volume and access to tools, considering that I don't know the exact internal configuration of components it is conceivable to think of part of the internal layout as some type of a tool carrousel that rotates around the interior.

Mobility with two rolling legs seems reasonable with the optional stability of a third tripod configuration also seems like a good idea.

So maybe you wouldn't end up with something just like R2-D2 but it might be very close.


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.