Why Choose Less Effective Armour Types?

Question

Full steel plate armour is seen as the most effective type of armour from the Medieval period, viewed by some as the pinnacle of medieval/early-renaissance armour. It’s rounded surfaces and layers of padding and chain mail underneath the plates reduced the wearer’s chance of injury drastically. It also allows for a high level of mobility and articulation without restricting the wearer too much.

In our own history, we have developed armour such as brigandine, lamellar, a coat of plates, segmented plates (like the lorica segmentata), gambeson, chain mail, we’ve even made armour out of wood and bone. However, none of these are quite as protective and mobile as a suit of full steel plate armour. Indeed, of these armours mentioned, some are more effective than others, almost in a hierarchy.

With this in mind, in a world where multiple types of armour co-exist in the same place at the same time, why would people actively choose not to wear the most effective armour, such as full steel plate, if it was available?

For this question, assume that monetary cost is not a factor. The reason for this is that it is fairly obvious that people would not buy better armour if they could not afford it, so cost of manufacture and sale should not be factored into answers.

Also assume that the availability of resources is not a factor. Again, it is fairly obvious that if you lacked the resources to produce more effective armour, you would have to produce something less effective.

The best answers should cover why less effective armour would be chosen on both an individual level (such as an adventurer, mercenary or other form of lone traveler) and a militaristic level (such as an army or other large group of organised fighters).

Magic and monsters may factor into your decisions but this is not required for a good answer.

Answer 1

I will structure my answer into three parts.

In the first one, I will be vaguely railing against the arbitrary restriction on the cost and other economic factors )

The issue here is not only in the straight up monetary cost. The biggest resource is the work time. Late plate armor needs a lot of effort of a fairly specialized professional armorer to produce. It's not a task that can be scaled by throwing more people at it, unlike the production of maille, for example. It also needs a lot of personalized fitting. So, it's not an item that can be taken 'off the shelf' or from the municipal armory - it needs to be ordered in advance by a person who plans to do nothing but fighting in the near time, or even for most of his life.

Another factor to consider - in the medieval army an armored knight needs a fairly large retinue. However your army is composed, someone needs to care for the horses, forage, build the camp, dig fortifications and latrines, help the knights to put the armour on, and so on. And unless your warfare is heavily ritualized form of mass joust, where non-knights are out of bonds and can't be attacked, it makes sense to arm and armour at least some of those people. So, every infantryman and squire would also need plate armour by your logic. Time being the most precious resource, you are not able to equip every one of those with fitted white plate, so by necessity munitions grade armour enters the equation - and it is 'worse' then knightly armour, being either heavier or less protective or both.

Moving to my next two points, I need to say that I actually do not quite understand your question. Seeing your replies above, I can't say which of the two are your asking:

1) why would any individual person choose 'inferior' armour if he has an access to full plate?

2) why would a nation in a world where plate armour is available, armour it's heavy cavalry and heavy infantry in inferior armour?

So I will try answering them in turn.

As for the first variant, the answer is party covered above. Any army has many more roles then heavy cavalry and heavy infantry. Actual fighting takes a minuscule proportion of the time any warrior or soldier spends in the field. Most of the time is spent marching, riding, putting up camp, sleeping, eating, standing sentry and dicing ) However comfortable full plate may be, you can't spend 24 hours a day in it. Some soldiers can opt for armour that is easier to put on and take off (one of the advantages of the brigandine, actually, is not the cost, but the ease of putting it on by yourself), or easier to do daily tasks in. You can dig latrines in full plate, but it's absolutely not optimal way to spend your time. 'Inferior' types of armour can have other logistical advantages - ease of field repair, for example.

Also, the soldiers that are not expected to enter melee would not wear full armour even if they had time to prepare. You can even see that on the the medieval miniatures the archers are drawn wearing full plate, but with open faced helmet and without gauntlets. So, archers, pikemen, siege weapon and artillery crews would not wear full enclosed plate.

The main idea in this part is - soldiers often sacrifice protection for comfort. And throughout the history, the average infantry armour is some sort of torso armour and open helmet. So unless the soldier absolutely needs full armour, he won't use it. It goes double for 'adventurers'. Unlike soldiers, they won't have an advantage of having the baggage train where they can stash their armor. If you have a group of adventures, one of them could be clad in full armour, while the rest serves as his retinue, helps him carry it, and protects him, while helping him to put it on.

Whatever the gripes people may have with good old Tolkien, the Fellowship is one of the best description of a group of adventurers in terms of their traveling kit - they have only two shirts of maille among them, one is worn by superhumanly strong dwarf, another weighs almost nothing, a single sidearm per person, while the main bulk of their belongings is spare clothes, ropes, water, food and occasional firewood. Compared to that, the more weapons and armor your adventurers have, the more unarmored helpers they need - servants, native guides, packhorses etc.

The answer to the second variant of the question is more complicated. It's also hard to answer, why a nation would not use full plate armour without resorting to the economic explanations.

The easiest case is isolation. The country is pretty isolated, it had it's own martial culture, own tradition of arms and armor and had only recently come into the contact with the 'mainstream' cultures of your world that use plate armour (think 16 century Japan). Some nations can be in the perifery of your world, or these are the peripherical regions of bigger nations. They have a constant low-level conflict with nomadic tribes, so mobility is a higher priority over protection (think the whole Eastern Europe on the border with Great Steppe for the most of the history). Some regions can be very distinct geographically, so it's hard to use heavy cavalry there - broken terrain, bogs, mountains, etc. (think Scottish Highlands). So, some specific local factors can prioritize light infantry or light cavalry as the backbone of the military in the region.

Different economic factors can also be in play here. The particular region can be poor in local resources, or not urbanized enough to produce plate armour locally. While it is possible to import, it adds additional complications, so that poorer local armour still becomes a more 'optimal' choice in a lot of situations. If you need it as a plot point, there can be even a trade embargo on a particular nation, where everybody agrees not to sell their better quality arms to them.

Answer 2

Comfort, individually

Plate mail is heavy and hot, which is why you don't want to wear it all the time. Instead, you'd strip down your armor while you weren't seriously expecting combat, leaving only the gambeson (cloth padding) or gambeson and chain mail. Much more comfortable, but now you're vulnerable.

Logistics, on an organization level

Let's say you've got an army. One of the important bits about your typical medieval army is how far they can march in a day for a given level of exhaustion. So your army isn't going to be wearing plate mail 24/7. If they're not carrying their armor on their persons, it has to be brought on carts. This means more carts, more draft animals to pull the carts, and more resources for those. It adds up. You also need more blacksmiths to help maintain the armor.

Training

First off, many medieval armies were levies/drafts, where they basically grab 1 out of every N men in an area. These are not professional soldiers and they would not know how to fight in plate mail, both because of weight and because of the vision impairment. It would take longer to train them in fighting in plate mail.

Don and doff

Plate mail is not easy to get into and out of. It usually required someone to help, and if your entire army is wearing plate mail, along with the gloves (that need to be secured) then you'll have problems.

This is also important because you can't always predict when combat will happen long enough in advance to get into armor. If you're sleeping, outside your armor (see comfort) then it will take you a bit to get into armor. In which time someone will probably stab and/or shoot you.

Trust

In modern times, we have these things called security clearances, because we don't trust everyone. You can't fly a fighter jet without passing a background check, nor will you be hired as an information security officer.

The same principle applies here: as a government, I don't want to give every Tom, Dick, and Harry armor that makes them very hard to put down. I don't trust them. That's reserved for my most loyal troops and bodyguards. With an equipment advantage, my palace guards and bodyguards can compensate for numerical or informational (i.e. ambush) disadvantages.

Answer 3

Armor was chosen based on how good it was for its actual purpose. This is the same way modern armies use to choose their equipment.

As an example the rifles used in the world wars had more powerful cartridges and were expected to be accurate to greater distances than modern assault rifles. And you could get them in automatic versions even. But starting in the 30s (I think) more and more armies realized that most soldiers never or extremely rarely shoot beyond 150 to 200 meters. Or need the extra penetration that a full powered rifle cartridge gives.

This means that the rifles are not really better than an assault rifle in actual use. Equipping your common soldiers with those will give you no benefit over using cheaper and lighter assault rifles shooting weaker and cheaper ammunition.

Same logic applies with arming medieval armies with armor. A plate mail is heavy and expensive armor designed for repeatedly getting hit by heavy weapons without taking lethal damage. And it works very well.

But most medieval soldiers do not actually spend that much time getting repeatedly hit by heavy weapons just like most modern soldiers do not spend much time taking long range shots.

Ranged and light units are supposed to avoid taking heavy hits altogether. Equipping them with heavy armor would just make them slower and encourage them to do things they really should not be doing.

Even normal front line melee units where soldiers do get hit with heavy weapons do not really need soldiers to take repeated heavy hits. There are other soldiers behind him who can take the next hit. So such units are equipped with armor that keeps them from taking lethal or crippling injury and keeps them fit enough to fall back.

So who does plate mail make sense for?

Heavy cavalry and heavy infantry. These units are expected to smash thru enemy formations where falling back would leave you alone surrounded by enemies. Or to take a charge without needing to fall back. And it is much easier for the unit not to fall back when individual soldiers do not need to.

Officers in other units usually can use extra protection as having them injured makes other soldiers less effective. You can also have specific elite soldiers with better armor in a melee unit. Typically they would also act as NCOs. This is because they have better abilities or even weapons as other soldiers so having them injured actually makes the unit weaker.

Adventurers in modern RPGs or fantasy are an important group as well. They need all the protection they can carry. Since they are most familiar group of people to use medieval armor to modern people, this kind of skews how most people see armor.

Answer 4

Mobility

The key benefit that lighter types of armour offer both individually and militaristically is not having to lug around an extra 25-50kg all day/during a battle. Well fitted full plate armour offers a surprising amount of mobility, and is in fact lighter than most chainmail hauberks, but compared to an unarmoured person it is still a significant amount of weight. This study (albeit with armour on the higher end of the weight scale) found that moving in armour takes about twice the effort as moving unencumbered, with the majority of the issue coming from the additional weight on the legs. It posits that this could have been one of the deciding factors for the English victory against greater numbers of very well armoured French knights at the battle of Agincourt.

However, that's not the only example.

The clash between lighter armoured troops and heavy infantry was very common in the ancient world. Between Greek phalanxes and Roman legionaries the heavy side is well covered, and plenty of 'barbarian' and 'civilised' cultures around them specifically chose to forsake heavier armour.

Example 1: Greeks vs Thracians

Early hoplites were heavy infantry that fought in close formation. Wealthy hoplites would be armoured in a bronze panoply weighing around 32kg, and less wealthy hoplites would usually be unarmoured aside from their large shield and large spear. Early engagements with the lightly armoured Thracians to the north did not go well for the Greeks.

Thracians usually fought as peltasts. They were unarmoured, with a small shield called a pelte, javelins and a short sword. When fighting a phalanx, they used their extra mobility to keep their distance and pepper the formation with javelins. If the hoplites broke out and tried to chase them down, they'd again use their superior mobility to retreat before picking off the stragglers and resuming the attack. Once the phalanx had been thoroughly disrupted by casualties, javelins encumbering shields and exhaustion the peltasts would close to finish them off. It was such a successful tactic that it was adopted wholesale into Greek military tactics, and the Thracians remained a feared people by the Greeks even afterwards (despite not taking up heavy infantry tactics themselves). They were also used to excellent effect by the Macedonian army of Alexander.

Example 2: Romans vs Dacians

The Dacians were a group of peoples from a similar location as the Thracians (perhaps even being a Thracian people). They were a wealthy people, benefiting from trade with the Greek colonies on the Black Sea and plentiful gold mines in their territory. During the 1st century BC two of their kings carved out a significant kingdom in modern-day Romania which had significant conflicts with Rome.

They're primarily remembered for their defeat marked on Trajan's column, but their empire lasted from 76BC-106AD (182 years), weathering Roman retaliation during much of that period. The wiki article seems pretty Romano-centric, focussing on their defeat by Trajan, but there's a hint to their capability in one of Trajan's motivations being to 'reclaim their standards'. The reason the Dacians had those standards in the first place is that they'd defeated two previous concerted military assault by the Romans.

The Dacians fought primarily as light infantry. They were certainly wealthy enough to outfit themselves with armour should they have desired, and some did with mail in the Celtic style. However, the vast majority fought lightly armoured and were successful against the Roman heavy infantry on at least two separate occasions. Their tactics and weaponry were so successful that the Romans had to modify their armour to protect against them.

In conclusion

If you get looking, there are plenty of other examples around of lighter troops prevailing over equivalent heavy troops, even in close combat. Romans vs the Spanish, Mongols vs Polish and Hungarian knights, and Roman Velites (peltast equivalents that were famed for their readiness to get into close combat, catching many armies by surprise).

With the correct tactics, weaponry and environment lightly armoured troops can be every but as effective as heavily armoured ones, and in many cases moreso.

Individual level

To touch on the individual level as an adventurer/lone traveller, you're unlikely to be walking around fully armoured the whole time due to the aforementioned double-effort it takes to move around. Knights didn't. They travelled around unarmoured and geared up before a battle.

As a lone traveller or adventurer, you're unlikely to be fighting many set piece battles. Most of your conflict is going to come without much warning, and you're unlikely to be able to get fully armoured up before you're fighting. Heavy armour isn't much use to you if it's sitting on the ground, and is just a burden to carry around if it's not used.

Better to pick something lighter that you can comfortably travel around in all day.

Answer 5

One answer is that the lesser armour type is lighter, and allows for more rapid troop movements and deployments. If said soldiers have to cross rivers or hike up mountains, lighter armour may be a necessity. Another answer is that full steel plate armor will become a lot hotter in warmer climates. This could be problematic an a desert environment. Another answer is that steel can rust. This might be an issue in a humid environment like a rain forrest.

Answer 6

Your limitation of unlimited resources takes out the most obvious answers. Is work going into the production of the armor not a factor either? Otherwise, this would be the most simple reason. Plate armor simply requires a lot of work hours from skilled craftsmen.

Without special circumstances there is no reason to settle for inferior protection, neither on a individual nor on a military level. If you can equip youself in a superior way without any disadvantages, why wouldn't you? (caveat here for militaries, sometimes the good old mass assault with arrow catching cannon fodder will still be superior, yet your resource catch negates this, unless manpower is also an unlimited resource or mass necromancy is a thing in your world).

Plate armor will also not limit agility or endurance significantly, as some people will certainly attempt to tell you. Even plate armor still allows you to do acrobatic tricks or scale a climbing wall (there are some cool videos of this in Youtube made by the Kingdom Come game developers). The endurence side of things can and should be fixed with training and drills. There might be people who are simply too weak to cope with plate armor, but they would fare poorly in combat against a plate user anyway, so there's no need to debate dead meat.

That all said, here are some circumstances where other armor might be chosen.

-Plate armor is ineffective: This is what happened irl. Guns simply got too powerfull, and the performence of plate armor wasn't worth the money.

-Naval warfare: Steel plate doesn't like seawater, and swimming in it gets awkward real quick. Naval landings turn out horrible if your equipment drowns you. (This refers to permanent sea troops (aka sailors)). You might still use platy boys (this is a real word xD) for specific operations.

-Magic: Strongly depends on the magic system. Yet if there is something some form of metal-bending (no pun intended) like in Avatar: The last air bender, plate armor becomes impractical and dangerous. On a similar note, many role play systems have metal interfere with spell casting, so there is a good reason why mages would wear cloth armor.

-Covert Operations: If you want to take a city with the help of infiltration forces, enemy guards will consider a bunch of people coming into the city in gambesons (which can be seen as normal winter cloaks), a lot less conspicuous than a bunch of platy boys. And if the mission will involve fighting, taking the most protection you can get away with is reasonable for individuals as well as for soldiers.

-Local Customs: This applies more to individuals. If plate armor is readily available, local rulers might decide to make private ownership illegal to have a military advantage over the people. So any adventurer will be forced to use the next best tier of armor: mail over gambeson.

-Prestige and Sports: In the Renaissance, rapier fencing was popular, as it was a test of style and skill. Platy boys bashing their heads in with halberds and half-sword techniques might be seen as clumsy and brutish. Going to battle (or rather duels) with no armor sends a statement and makes winning more prestigious. Maybe there is a tradition that dictates armorless fighting under certain circumstances.

-Logistics: Your infinite resource caveat limits this, but this is a serious limitation. Plate armor is maintenence heavy and heavy in itself. A Gambeson only needs sewing kit, but plate needs a forge and a skilled blacksmith to fix. Likewise plate might not be ideal for jungle warfare and especially an army needs significant infrastructure to supply plate to everyone.

-Tradition and Culture: A weak one, as any culture that is technologically inferior will be conquered quickly, but "we've always done it this way" can be a strong argument.

-Plot Armor: I said no one would go for suboptimal armor, but in a medival setting plate armor isn't the strongest armor, plot armor is. Why would your hero, or any main character, bother with any type of armor if they can't get hurt anyway.

TLDR: Under your limitations there is no general good reason to settle for inferior armor. There are a number of exceptions, the only general non-quirky one being anti-armor magic.

Answer 7

Armour trades mobility for protection.

Your basic assumption is somewhat wrong:

"[Full plate armour] allows for a high level of mobility and articulation without restricting the wearer too much."

Mobility

Whilst good plate armour does allow mobility, it's certainly not full mobility. I fight HEMA, and even lightly armoured gloves limit your wrist movements; this is why there are heavier gloves for longsword than side-sword than rapier (which require more mobility and finesse, but do not take such heavy strikes).

Endurance

Furthermore, whilst troops in plate armour can run, they tire quickly.

One study showed people used twice as much energy moving in it: https://www.popularmechanics.com/culture/a6749/medieval-knights-on-a-treadmill-put-historical-myths-to-the-test/

Many battles or other tasks require endurance, and wearing full plate armour will greatly reduce endurance. Tired troops fight badly, and are easily out-manoeuvred. In a formal pitched battle with both sides using plate armour, this obviously affects both sides equally, but in any other scenario, it's going to hurt the team with plate armour if the other side can draw out the conflict (e.g. by retreating).

Particularly for roles such as adventurers or travellers, plate armour would have many drawbacks, and would not be practical to wear continually. It could be carried on a horse pack, but this would then mean you're not wearing it most of the time.

Answer 8

Say we have a knight in full steel armor, fighting a guy in practically nothing. Certainly, the armor should be useful. However, fire and blunt weapons will both be worse for the knight, because dodging is presumably far harder. A skilled fighter also may opt for lighter armor to outmaneuver the knight, such as using a sword (armor blocks slash attacks), and stabbing joints with the faster and more accurate movement the light/no armor can allow.

Perhaps armor stands out. A knight in full metal must be a clear target to raiders than what appears to be a poor "unarmed" beggar/peasant.

Armor also is very annoying in terms of heat (protective fencing gear is bad enough with sweat, I'd hate to imagine 60 pounds of armor).

Traveling also would probably be bad in armor. I highly doubt armor is comfortable for normal situations, nor would I believe knights would always wear armor at all times (sounds like paranoia to me).

Another thing I'd like to note: Spartans would go into battle mostly naked with a shield, breastplate, and helmet. I don't have any idea of the accuracy to this statement, but this getup will already weigh more than 50 pounds in metal, explaining why minimal armor would be favorable. EDIT: Clarification, "naked" as in wearing no more metal armor except the helmet-shield-breastplate combo. Cloth and leather being ignored here. Thanks to pluckedkiwi for pointing out my vagueness.

As a final side note, there is something called the "murder stroke", slamming the hilt of a sword into a helmeted person's skull. Regardless of armor, the impact should still kill. If I face a swordsman of considerable skill, I personally would take the no-armor route and sprint full speed away from them, if I could.

Answer 9

Terrian

full Plate is fine is in relatively flat land in a temperate climate, but that is not the majority of the world.

In a hot humid climates plate has far to much insulation, you will overheat far too easily. It becomes impossible to wear it for any length of time. This is still a problem in hot climates in general but humidity just compounds the issue.

In swampy terrain the added weight makes you prone to sinking and getting stuck, worse the padding can get very heavy when wet, weight becomes a major problem.

Naval combat, plate is a deadly in naval combat, if you fall in the water, you die, period. Of course this only matters in navies where the people could swim, which was not all of them. Worse ships are often tight cramped spaces that demand a lot of climbing and squeezing through tight areas the very things plate impeeds. There is another hidden problem exposed polished iron and steel and salt water spray are not a great combination european style full plate will rust pretty quickly.

Archers, archery produces a unique problem with armor, the proud chest plate and flared joints that makes plate armor effective also gets in the way of of a bow, even the most heavily armored archers the early samurai had armor with less coverage to eliminate anything that might impede the bow.

Answer 10

Just want to throw in an aspect here.

In the Bloodborne Game for PS4, armor and protective gear were used in the beginning to protect oneself from injury when fighting a mysterious outbreak of werewolf-like monsters. The lore and backstory state that this armor was found to be too cumbersome and didn't really make a difference anyway when fighting monsters of the strength and size that they faced. So armor was in general, discarded completely and replaced by light cloth and pieces of leather to protect from surface injuries and scratches.

The new and light attire enabled the "hunters" to move swiftly and dodge the monsters easier and thus have a higher chance of survival than wearing armor that didn't work anyway.

Answer 11

Why do you want there to be different types of armour? If it to create some interesting dynamics then something natural to those dynamics that you seek after would be the answer.

Terrain The full steel plate men could dominate the plains while the leather guys would have the forests to themselves. This would create scenarios where neither parties want to get off their preferred location.

Skills and weapons Wizards with anti-plate skills such as rusting. The spell hits only one piece, so it is ineffective against chain mails. Molotov cocktails or such would make full plates quite an oven. There could be a muscle grow skill/potion. Moving in too big armour is not possible and too small armour would make the user be crushed.

Deus and his ex machinas would always favour someone or grant access to magic. Some are more favoured by the god, for example, those that do not use metals, wood, leather, magic... Many gods having their own preference on whom to support. Does the forest god like or dislike people using wooden shields and animal hides? Or if the god just has an eye for certain aesthetics.

Answer 12

Effective is a relative term

Armour is a tool to do a job. Sometimes a sledge hammer isn't the best hammer to use. You need to consider what the job is to select the best tool.

Weight, speed, flexibility, noise, bulk, cost and what you're up against is just as important as protection.

Something good for bullets isn't always the best for knives and what's good for knives isn't as good for blunt weapons.

Choose your tools to fit the job.

Answer 13

You want to evoke a tough martial mood, but you don't intend to fight.

https://www.p66.me/cpa

Impractical, expensive and really great looking weapons and armor have probably been around almost as long as real weapons and armor - ceremonial maces, decorative swords, parade armor. All that stuff is what you often see in museums because it never got down and dirty, and is sweet eye candy, and costs loads, so people kept it safe. Rich (men, usually) want to show off their wealth and importance but don't want to seem like wusses and so they glam up their military regalia. Authors and artists of fantasy want to show off the bodies of their sexy heroines, who will get hurt in battle according to authorial discretion, not efficacy of their armor.

People in your world might (under the right circumstances) wear less-than-optimal armor to evoke the mood of real, practical armor but in a way that is more beautiful and spectacular than ordinary working armor can accomplish.

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You are hard pressed, and grab what is handy.

Defense Secretary Robert M. Gates has reassured Specialist Zachary Boyd, stationed in Afghanistan, that his military career is in no danger for having appeared on the front page of The New York Times dressed for combat in pink boxers and flip-flops. Quite the contrary.

https://lens.blogs.nytimes.com/2009/05/21/behind-the-scenes-man-in-the-pink-boxers/

If you have a big budget and leisurely access to your neighborhood armorer you can have him make you a nice suite of full plate. If you wake to find the battle has started on your front porch, you might grab your big jacket and go. People in actual battle might not have had much time to set up. The pink boxers soldier did get on his helmet and flak jacket and then it was time to start shooting.