Why are my soldiers weapons so ineffective, or the rarity of one-hit kills

Intruder alert! Intruder alert! The alarm blares in the control room. The security cameras focus on a group of people who shouldn't be there, who are carrying comically oversized weapons. The guards are sent to intercept. They have machine guns, guard dogs, flame troopers, and even some missile launchers. Against infantry.

The guards arrive, and after a verbal exchange a fight starts. The guards start firing their
various weapons into the intruders. Tens, then hundreds of bullets hit them. They keep on walking. > Grenades, missiles, lasers, all shrugged off.

Could I please have a sensible in-universe explanation for why the weapons used in this universe, and a lot of others are so ineffective? Who do I fire?

So, what I'm asking is why is it that in a lot of combat games, especially fps-es, one can take a stupid number of bullets before dying.

Edit: please note that people are getting hit by bullets (and possibly swords), and it doesn't matter who is fighting against who. Gang fights, bank robbery, actual international war, everyone just soaks up bullets.

This question was originally inspired by what I have seen on YouTube of the Final Fantasy 7 remake.

• Doom-guy levels of plot-armor, of course. Games that encourage you to charge into a wall of bullets like an idiot has to give you some level of superhuman resistance so that you don't die like a normal idiot would in the same scenario. The difference is whether the game actually bothers to acknowledge this armor in the form of a supersuit and/or supersoldier mods or just shrugs it off as "the protagonist is just really good". – ProjectApex Jul 2 '20 at 12:49
• Once I attended a seminar given by a researcher who, as hobby, demonstrates the unphysicality of some movies. He showed that, even firing at complete random, starshiptroopers should make a tea filter out of the intruders on the Death Star. – L.Dutch Jul 2 '20 at 12:58
• @L.Dutch-ReinstateMonica sounds like an interesting seminar – Mark Gardner Jul 2 '20 at 13:24
• @ProjectApex are you saying that (pretty much) everyone in the universe has such insane plot armour? My thoughts are that people who want weapons would want better weapons then. – Mark Gardner Jul 2 '20 at 13:24
• 3.5 stars fleet admiral: "cease fire! please treat this exercise seriously... I want to see running not walking! and which idiot shot me." – user6760 Jul 2 '20 at 14:10

Ablative Body Armor

We all think that in "real warfare" it's one shot one kill, but for the past few decades, that have been becoming less and less true. Many armies now equip thier soldiers with body armor that includes ceramic plates that can stop most battlefield ammunition. These ceramic plates are typically rated as class-IV body armor meaning that they can stop pretty much any kind of handgun, submachine gun, assault rifle, LMG, and most sniper rifles even if they are using "armor-piercing" bullets. But once they are hit they shatter making them useless against follow-up hits.

And that is just where tech got to about 20 years ago. Ablative body armor is still getting better. Another recent development is the use of shear-hardening polymers that are used to treat modern kevlar body armor. SHP treated kevlar becomes so hard under impact that it becomes like a ceramic plate. SHPs make kevlar about 4x as strong for thier weight, but like all hard things, they break instead of bending. While the SHP coating itself re-liquifies after being hit, allowing the armor the take multiple strikes, the underlying kevlar can be sheared from impact weakening the armor as a whole.

Apart from armor getting lighter for its stopping power, armies are beginning to equip thier infantry with robotic exo-frames. These robotic suits allow a soldier to carry several times as much weight as he could unaugmented meaning that in the very near future one can expect infantry armor to more closely resembled that of a light tank or APC.

With the kind of military grade body armor you will see in the not so distant future, not only is your description possible, but it seems inevitable. Unless someone figures out how to make a much better bullet, the best way to take out such a target would be to riddle it with high caliber bullets shattering the ceramic plates and shearing the kevlar fibers, until the armor becomes weakened enough to penetrate or you need to nail it with a direct hit from an anti-vehicle scale weapon like an RPG.

The reason people still use assault weapons in this scenario would be the same reason they still work in video games. RPGs are big and heavy, and only one-shot on a direct hit. The cost of ammo in terms of both manufacturing and weight make giving everyone RPGs impractical; so, most troops are still given automatic weapons because in the 2-3 seconds it takes to line up a shot to make good and sure your RPG will hit, an assault trooper could spray and pray 20-30 shots into someone's gut waring his way through the armor for the kill.

• In the case of ceramic plates, it isn't just (or even mainly) their hardness that counts. The fact that they shatter is actually a major reason why they work - the energy goes into pulverizing ceramic instead of being transmitted to the wearer and breaking bones. Any futuristic armor with hardened plates needs to account for where all that kinetic energy is going. – Cadence Jul 3 '20 at 5:11
• @Cadence I believe we are actually saying the same thing. Note, that I cite the ceramic plates for their hardness, not their toughness. Hard things shatter instead of deforming; so, hardness is the material property that gives you the effect you are referencing. – Nosajimiki Jul 4 '20 at 14:47

Soldiers in your army will have the best weapons that you can economically provide for them, and will tend to be brutally efficient (and not take stupid risks like walking across an open hangar into gunfire when cover is available).

Gladiators on the other hand are equipped to put on a show. They are given exotic or visually interesting weapons, not economically effective ones, and they are rewarded for putting on a show. Whether they are slaves or celebrities, they're incentivized to be foolhardy and dramatic, not to hide behind cover.

So, could you rewrite your story in such a way that the battles all have an audience and, in that setting, the pleasure of the audience is more important than the lives of the soldiers?

• Sorry, nice idea, but it doesn't line up with (for instance) the quoted scenario (small team invading a semi-military facility). – Mark Gardner Jul 2 '20 at 14:37

Inverse Ninja Law

The inverse ninja law is a media trope regarding not only ninjas, but any character type that is shown to attack in massed numbers, such as soldiers, robots, daleks, or vampires (but not zombies). It states that the threat level of any number of ninjas or other whatsits is inversely proportionate to their numbers. Therefore, if you're attacked by a lone ninja, you're in trouble, but if you meet an army of ninjas, they're going down.

Also present in TV Tropes:

A specific form of Plot Armor, this trope is very common due to the numerous storytelling considerations fueling it. Drama thrives on conflict, and having the few put up a fight against the many is basically a free conflict coupon that's automatically viable during any few vs. many confrontation. Why have the superhero team curb stomp the villain if you can make him powerful enough to force them into Teeth-Clenched Teamwork? Why have the dozens of Mooks club The Hero unconscious three seconds into an encounter if you can let him take down seven or eight of them before he collapses, to show how much of a badass he is? That would be letting some perfectly good dramatic tension go to waste.

(...)

In other words, if Team Meager is up against Team Gargantuan, we probably know something about Team Meager and at least care how well they're going to do in this fight—maybe we even outright sympathize with them and root for them to win. Team Gargantuan, on the other hand, is likely a faceless blob of Mooks or Red Shirts that we don't care about on any personal level. Letting Team Gargantuan steamroll over Team Meager in this scenario would be anticlimactic; not letting Team Gargantuan do that means playing this trope straight almost by definition. Often Team Gargantuan instead of applying their numbers, tends to get in line waiting to get beat in turn.

Your problem is hiring too many people to fight a lone attacker. It doesn't matter if you are the good guy or the bad guy. Luke Skywalker defeated the Empire alone, but Anakin Skywalker also defeated the Jedi Order alone.

The most cost-effective solution is to fire all your forces and hire a hero, or at best a party of heroes. Sure, they might be expensive, but in the end they might be cheaper than the combined costs of your whole army. It may also be that losing will necessarily be way costlier than otherwise, so put some money on that small team.

Warhammer 40k-style Void Shields

A void shield is an energy shield that shunts things of suitable energy/mass trying to penetrate the shield into an alternate dimension (the warp, for 40k, hyperspace or N-space or wherever in your universe) but only as long as the power lasts.

So your gallant heroes arrive at Evil Facility X. They are each equipped with a personal void shield. Lets say for ease that this shield is molded to either their bodies or specialized clothing. Now a void shield is variable. It can be cranked up to stop a nuclear blast but permit a bullet to pass through, or cranked down so it could stop a bullet but allow a knife, or allow a knife but stop molecules drifting through. Or even be a barrier impenetrable to any level of penetration. But the catch is, it only works until the battery dies. And the energy level of whatever is passing through correlates to the drain on the power.

So if a void shield gets hit by a bullet which imparts X force, or 50 knife blows that also equal X force, the battery is drained the same. It then becomes a balancing act. Do I hope my body armor/skill is enough to protect me from low-energy attacks, and save my void shield for rockets only? Do I set it for bullets, just in case? Or maybe even lower, so that pesky flamethrower can't roast me? If the Evil Mooks are all armed with the same type of weapon, or weapons at the same energy level, it's a no-brainer. BUT if your enemy is attacking you with a whole host of weapons you have to cover ALL those impacts. Sure you LOOK invulnerable at first, but eventually your void shield can't handle any more damage and you die.

"But why aren't all the mooks armed with rocket launchers?" you ask. For the same reason modern troops aren't all armed with rocket launchers. It's inefficient. Sure YOUR strike team has the Best and Greatest void shields. But Rival Evil Scientist's ninja strike team only has mediocre ones. They'll stop a bullet or two then wear out, so a three-round burst from a submachine gun'll put paid to them. Cheaper, less mess, and the Mooks don't have to lug rocket launchers everywhere As to flamethrowers, they're less likely to blow out a wall, and are great for shield-draining as they cover a wider area of the void shield than a single bullet, and have the advantage of being able to shoot around corners!

If you wanted you could even impart some sort of "diminishing" effect to your void shield. So instead of totally absorbing a bullet it could instead absorb a certain amount of its mass or energy. With the right setting instead of killing you a bullet would instead only scratch you. Not as efficient as total blockage, but also uses less battery so your void shield stays active longer.

• Now here's an idea: biological void shields. nice answer by the way, and welcome to the site. However, please read the note at the end of the question that specifies that nearly anyone can survive machine gun fire. Not just people who can afford these things. – Mark Gardner Jul 2 '20 at 15:34

Excessively Armor-Piercing Weapons

Some properties which make a weapon armor-piercing also reduce the damage they do to a soft target. Against an unarmored human, hollow-point bullets are more effective than armor-piercing or full metal jacket because the HP expands and spends energy in the target where AP or FMJ might overpenetrate.

Of course a 5.56mm hole or thereabouts all through the torso or a limb is nothing to shrug off, except for western heroes. But your futuristic weapons might take it even further, being designed to make relatively small holes into heavily armored robots.

• Sabot flechettes can be quite small in caliber but extremely good at armor piercing. – DWKraus Jul 2 '20 at 22:27

Ineptitude of technology versus efficiency against natural defences. The "humans" in your scenario could be superhuman, and the weapons are simply not strong enough to do any decent damage. Due to some reason or another, the best weapon the technology in your world can create is very inefficient for its purpose, and hardly does any damage to the target. But it is all you have, there simply isn't anything better.

If you created a humanoid race with a thick enough skin structure that a blade can't cut, and a bullet won't penetrate, then the effectiveness of any weaponry will diminish significantly. Without a significantly more potent, or larger amount of gunpowder, its near impossible to damage these humans. But using this (amount of) gunpowder will significantly increase damage to the surroundings, so its not done unless there is another choice. Not to mention supersizing the technology to increase efficiency makes it unwieldy.

Probability-manipulating healer nanites: Unbeknownst to the population at large, alien nanites have crept into our world. The aliens are spreading them to people for inexplicable alien reasons, and they give humans access to alternative dimensions where intelligent beings actively seek interaction with our universe (for fun, entertainment, study, or any reason you want). This alternate universe access lets these beings shift probability in our universe, so bullets always fire so as to miss, air molecules divert trajectories, flies jump in front of laser beams, and bomb fuses fail to trigger. The beings want to keep their chosen test subjects/entertainment alive. These nanites are also able to rapidly heal people - not so much they realize it, but if you're used to being recovered from a gunshot in 15-20 min (except for a superficial wound) you might not realize it's that exceptional. intelligent intervention means the more you question the effect, the worse you'll get hurt. Given human ego, they assume they're all Rambo or VanDamme, and charge into absurd situations because they've always been able to in the past.