I caught the edge of a discussion (I think sparked from an Edge Lit panel, though I’m not 100% sure) about whether you can justify using swords in a setting that also has ready access to guns. Most of what I caught seemed to suggest that the consensus was “no”, but the mills of my mind have since churned up a fair few counter arguments (many of which may have been independently rehearsed in parts of the original discussion that I missed).

Firstly, however, why is this such a trope? It’s not as though, in the modern world, soldiers aren’t taught close combat techniques, or that people don’t get down to knives and the like, but swords have been no more than dress uniform accoutrements at best for a long time, close combat tends to mean unarmed, and I don’t even know if bayonet drill is something actively taught any more. The fact is that guns are a very effective way of killing people, and yet they lack a certain something in style. Fantasy and certain kinds of SF thrive on a particular sort of romance and nostalgia that guns don't readily satisfy but swords definitely do. Despite “gun-fu” sequences in films like Equilibrium or The Matrix, there is an elan attached to swordsmanship that leads to a disproportionate showing for mêlée weapons (and here I’m meaning more than just “carries a knife as a back-up, but actually swords, pikes, axes and their SF equivalents, used as a significant part of a soldier’s offensive potential) in SF settings, or in fantasy settings where there are better ways of going about things (like late-period Shadows of the Apt, ahem ahem).

Let’s take that as a given, then: so you want to have your SF setting (or flintlock fantasy or whatever) with a side-order of swords, but you want to do more than just assume that your far-future space marines all carry sabres and are trained in their use for no earthly reason at all. What’s the rationale? Below are a few I’ve put together (and, in some cases, taken apart again) and doubtless there are more.

1. Guns are rubbish

This sounds like a bit of a cop out, but it's probably the most solid for fantasy or pseudo-historical settings  rather than SF (unless your advanced alien culture has some remarkable gaps in its tech tree), but there were centuries of real history where gunpowder troops went into battle alongside archers, crossbowmen, cavalry, pikes and all the rest. Early firearms made impressive noises but were slow and unreliable. If you’re writing flintlock fantasy or anything drawing from earlier history then you can mash up cannon, muskets, swords and what have you and feel property historically plausible. This also covers post-tech settings where guns are present, and may be very effective, but people can’t reliably maintain them or build new ones, hence you’ll never have enough guns to outfit your whole army.

2. En garde, sir

Perhaps there is a cultural fetish for duelling (as in Lee's Ninefox Gambit setting for example). If it’s anything like the real world this is probably an elitist thing, and so not really a solution to the “soldiers with swords” problem, but if duelling is a big cultural thing then maybe your two opposing nobles wave off their soldiers and have at it with their flashingsabres to see who’s the biggest nob, so to speak.  This is unlikely to result in entire battlefields of clashing broadswords while the space station charges up its death ray, but…

3. We don’t do it like that

It is also possible to have a cultural consensus that leaves military technology with one arm tied behind its back. If you have a setting where everyone works to a common societal norm, and that norm is basically designed to avoid full-on total war in favour of something more limited and genteel, then maybe people who could technologically afford guns, tanks and weapons of mass destruction do limit themselves to swords, perhaps because they're sensible enough to prefer an absence of mass destruction (fancy!). This seems utterly daft but Italian Condottieri apparently just danced their armies around each other rather than getting stuck in and dying for their paycheques, which makes perfect sense when every army is a mercenary one. Also, I've seen it claimed that Aztecs and their neighbours went to war to capture prisoners for sacrifice as a primary objective, both for armies and for the glory of individual soldiers, which is a considerably more difficult thing than just killing someone, and which philosophy, played to the technological hilt, is unlikely to result in the machine gun nest. The downside of this sort of set-up is if someone comes in from the outside lacking the same cultural mores and is more committed to victory at any cost, which would upset such a system very quickly.

4. Don’t shoot that thing in here!

So what if your guns are too good? If you’re fighting somewhere vulnerable to explosive decompression, say, or where the atmosphere can go up like a torch, maybe conventional firearms aren’t your tool of choice and you could end up sending your space marines on boarding actions armed with axes and spears. I’ve not convinced myself, with this one – I suspect that if such a situation arose in the real world, the solution would be some alternative missile weapon like a spear-gun or high-power air rifle – something that didn’t have the same force or penetrative powers as a bullet, but which could still be used at range. However, the possibilities of speculative fiction are endless. If your kevlar equivalent is very good, for example, you may end up with a situation where your non-explosive gun-substitutes aren't cutting it, and you end up having to scissor people out of their armoured suits the old fashioned way. Which is also the case with…

5. The guns, they do nothing!

So perhaps you and/or your opponents are bullet-proof, and yet somehow not sword-proof. This is another slightly dodgy proposal. Let’s say you’re like a D&D skeleton and piercing blows don’t worry you much, or the enemy is a zombie whose decapitation by axe is easier than a pinpoint shooting between the eyes with a pistol. However, the solution for a modern army would probably be something more like a rivebow from Mieville’s Perdido Street Station – a crossbow that throws a rotating saw blade – than a sword. However, one of the most famous SF settings of all time pulled this off – the shields in Dune allow slow strikes through but deflect swift ones. In the films they’re something of a noble’s toy (see duelling above) but you could have a similar device that was universal, negating the use of personal firearms.

6. Not as clumsy and random

Next up, how about your sword in itself permits some defence against firearms. Star Wars lightsabers deflect blaster bolts, allowing Jedi to take on legions of gun-wielding mooks. Of course the Jedi are special, and most Star Wars combat is still a ranged affair, plus SW blaster bolts are remarkably slow, enough to be plausibly deflected by a super-aware swordsman. Generalising this position into something where everyone carried a sword as standard would take a bit more stretching, but perhaps you mix it with the above and give people energy shields that can't be shot through.

7. Swords of ultimate doom

In Warhammer 40K, mêlée weapons often hit incredibly hard – you’d rather be shot by a gun that fires actual explosive bolts that actually explode inside you than be slugged by a power fist, for example. This also covers lightsabres, which can shear through armour and robots and the arms of luckless aliens without slowing overmuch. Perhaps your mêlée weapons are just that good, worth all that training and lugging around, just so you can bring the house down should you be able to close with the enemy.

8. Up in your face

Fighting in twisty, turny caves, or in the close confines of a spaceship. Guns are all very well at range, but if your army (or just some specialists within it) will spent a lot of time in environments where you can’t see the enemy before you turn a corner and they’re nose to nose with you, perhaps you give them swords? Actually, most likely you give them knives, which don’t quite have the same panache, but the thought is there. It’s hard to think of a situation where range makes a sword the perfect weapon, though – if your enemy is six to eight feet away then you can shoot them very well with a pistol.

9. Transporter-fu

So what if you have all the open space you want, but you or the enemy, or both, can cover it very swiftly indeed. There is a weird mix of ancient and high-tech weapons in Wolfe’s New Sun books, but one thing they have is incredibly fast cavalry, far swifter than real horses. If your cavalry is fast enough that you won’t take more than a single round of shot on the way in, perhaps you do still have swords. Alternatively, if you’re fighting xenomorphs, genestealers or the bugs in Starship Troopers, which can come out of the ground/walls and jump you, or fly at you very fast (Shadows of the Apt-style) perhaps you eventually start training your soldiers to whack away with axes and broadswords because you can’t guarantee the enemy will stay at a civilised distance. For less monstrous armies, if your wizard or your starship’s transporter chief can just teleport squads right into the faces of the enemy, then mêlée weapons may well be the most useful thing you can carry (power sword in one hand and pistol in the other like a pirate in a boarding action) because you’ can’t rely on making use of the range of your rifles.

There must be scads of others — please comment below if any occur.