Are there still advantages to bladed weapons in a futuristic setting? (Assuming sci-fi weapons like laser guns are commonly used in the setting) There are obviously uses of small blades like knives, but are swords still plausable? I’ve seen a few shows and books set in the future where energy swords or similar weapons are used
Without accounting for specific situational factors, no. Once you have ranged weapons that can be used to quickly neutralize multiple opponents in short succession, and remain viable at melee ranges, there’s no real place for a pure melee weapon.
Knives, axes, and hammers are something of an exception because they have value as utility tools, that can double as an emergency weapon. Though, I am reminded of the email in Doom 3 questioning a shipment of chainsaws to Mars. It’s probably worth remembering what those tools are used for before you simply drop them into your ship’s storage locker.
While we’re on the subject of using tools as emergency weapons and video games, I’m also reminded that most of the arsenal from the Dead Space were re-purposed mining and engineering tools. (At least in the first two games, anyway.)
So, that’s without specific settings that would justify the existence of a sword in your space opera. There’s, obviously, quite a few science fiction settings that do gleefully chuck a box of swords at the combatants and force them to sift through for various reasons.
The primary reason you’d be seeing swords in sci-fi is cultural. Lots of settings envision a distant future where culture has degraded to some prior point for whatever reason. Dune is probably the ur-example here, where human civilization has been reduced down to a feudal state, governed by noble houses. In a setting like that, you could easily see the sword used as a ceremonial weapon, in duels, or other specific circumstances. To be fair, Dune also replaces the sword with daggers for mostly aesthetic reasons, but the effect is still similar. Dune also challenges the use of ranged weapons with body shields. These, expensive, items block kinetic ranged weapons, and detonate in a nuclear blast when struck with lasgun fire. So, there’s an exemption to the ranged only rule above.
The lightsabers from Star Wars are another special case. In the hands of a trained force user they can (effectively) negate incoming blaster fire, meaning they do offer an exemption to the ranged rule.
Warhammer 40k finds a similar exemption by simply increasing the resilience of its inhabitants until you have a setting where fans sarcastically refer to energy rifles capable of reducing humans to red mist as “flashlights” because they do nothing to many of the setting’s inhabitants. To be fair, if something can survive direct lasgun fire (40k “borrows” the term directly from Dune), you’re probably not going to get very far swinging a mundane sword at it.
Because, sci-fi settings encompass such a massive range of potential environments, it’s probably important to point out that there are a lot of reasons you might see melee weapons on the loose. The above just a couple possible reasons, but let’s codify these without tying them to explicit examples.
Ceremonial usage is a big one. This means you probably wouldn’t see swords being used during boarding actions, but you would see them around, and people from the social classes who needed them could be reasonably expected to know how to use them should it be the most expedient option. This could be because civilization has degenerated into a kind of clan or great house structure. Generally speaking, ritualized dueling works in a system where you have disputes between individuals, but can’t politically afford to adjudicate punishment. This makes the most sense in feudal systems, or intra-faction conflicts in an unstable coalition. Again, Dune‘s Great Houses are an excellent example of this kind of situation.
Another big, potential, reason is if ranged weapons are rendered ineffective or risky in certain situations.
One of the classic examples is using high power kinetic weapons on a starship where you’re risking a hull breach with every gunshot. Depending on the nature of your energy weapons, (and the overall technologies used for maintaining structural integrity) this may be more or less of a consideration. If your setting’s ships can use force fields to maintain atmosphere punching a hole in the hull with a stray gunshot will be far less dangerous than if that means the ship is losing air, with no way to replace it. As your weapons become more powerful, this risk becomes more significant. That said, the hull breach situation comes with a mix of other considerations. If your setting has body armor that can resist small arms fire, it’s likely that your ships would share that construction. It’s also entirely possible that boarding teams would operate in sealed environmental suits, capable of exposure to hard vacuum, and more ruthless groups might intentionally trigger hull breaches during their boarding actions. The risks involved may also heavily depend on kind of ranged weapons your characters are using. Kinetic weapons with very high penetration may pose a much greater threat here than handheld particle beam weapons.
Another potential situation where you have technologies specifically designed to suppress the effect of specific weapon types. Personal shielding technology, or exosuit armor are potential examples. Of course, if it is armor, simply pulling out a sword probably isn’t going to do much, unless the sword circumvents the armor somehow. But, if you have a setting where body shields that can survive multiple plasma hits are semi-common, you might very well see people using swords, or similar weapons, to bypass them. To, be fair, you may also see the development of new weapons designed to bypass or overload those shields, so it’s not like this automatically means you’d see melee weapons.
Another possibility is when dealing with primitive cultures. If you’re dealing with a post-apocalyptic sci-fi setting, where some prior galactic civilization fell, leaving colonies cut off, you might come across planets where advanced technology fell completely out of use. I’ve argued against this in a strict context of post-apocalyptic settings before, but colonies introduce a new wrinkle, where you could potentially have a population base who knew how to use advanced energy weapons, did not have practical knowledge of kinetic firearms, and lost access to the latter. This could result in a full on regression, over a long enough time frame (figure several thousand years, at a guess.) So it is, theoretically possible you might have lost colonies that have regressed back to spear and bow warfare. What happens if human ships visit one of these lost colonies is, of course, up to you.
There is one hard part when it comes to defining a state of existence for science fiction, and it does show in this question. I used a few examples. Star Wars is generally accepted as existing in its own timeline. It’s science fantasy, and that’s fine. Both of the video game examples, along with a lot of sci-fi settings like Star Trek are near future. They’re set within one thousand years of present day. Stuff like Dune or Warhammer 40k are a lot harder to pin down. Dune is set sometime in the 24th millennium, and 40k draws it’s name from being set in the 41st millennium. Both of those settings juggle their overall technology by technological dark ages, but it does start to peal the lid off questions of, “what will the technology look like?” Meaning you need to address those concepts in much more general terms.
So, in short, “probably not,” but you might be able to assemble a setting where swinging swords around like it’s the golden age of piracy does, in fact, make sense.