Overview

What follows is just a general guide to many of the various real forms of armour that has existed over the centuries and their constituent parts. This is by no means a full guide but just one to cover the types found in many current works of fantasy fiction, with particular attention paid to games like Dungeons and Dragons and the like. In this following section, I will be taking the equipment list from D&D Fifth Edition as a main point of reference but htis is by no means restricted to that one game. I intend to make this as system agnostic as I can. One note I will add, in D&D there is such a thing known as 'padded' armour. This did exist in history but the correct term for it was gambeson. As such this will be referred to by it's correct term from here on in.

Boiled Leather

Also known in French as cuir bouilli, as mentioned earlier on in the fantasy tropes section, leather armour was very prevalent in the middle ages. This became less popular in later medieval times due to the availablity of other, better forms like chainmail.

Various recipes for making boiled leather have survived, but each of these conflict with each other. there may have been various different recipes, partly reflecting different final uses. Vegetable-tanned leather is generally specified. Scholars have debated the subject at length and attempted to recreate the historical material. Many, but not all, sources agree that actual boiling of the leather was not part of the process, but immersion in water, cold or hot, was.

Boiled leather was treated so that it became very tough and rigid, nothing like the supple leather outfits you see in some movies (Anne Hathaway's Catwoman and the Underworld series of films spring to mind). This material was also able to hold various forms of moulded decoration. As far as armour goes, this material was used for cheap, light protection as it was far cheaper than plate. The trade off to this was that boiled leather was far less effective at protecting the wearer. However, cuir bouilli could be reinforced against slashing blows by the addition of metal bands or strips, especially in helmets. Modern experiments on simple leather armour have shown that it can reduce the depth of an arrow wound considerably, especially if coated with a crushed mineral facing mixed with glue, as one medieval Arab author recommended. But this did not stop the arrow so the wearer would have still been injured. 

The word cuirass for a breastplate indicates that these were most likely originally made of leather. In the Late Middle Ages, the heyday of plate armour, cuir bouilli continued to be used even by the rich for horse armour and often for tournament armour, as well as by ordinary infantry soldiers.

Next on the list for classic fantasy is the 'padded armour'. As mentioned before the corrrect name for this was gambeson. This is a padded defensive jacket, also known as an aketon, padded jack or arming doublet, could either be worn on it's own or in conjunction with mail or plate, in order to cushion the body and prevent chafing. This also added a layer of protection against some blunt weapons such as hammers or maces.

Normally made of wool or linen and produced with a sewing technique known as 'quilting', the stuffing of which often varied from scraps of cloth or horse hair. An arming doublet (also called aketon) worn under armor, particularly plate armour of fifteenth- and sixteenth-century Europe, contains arming points for attaching plates. Fifteenth century examples may include goussets  sewn into the elbows and armpits to protect the wearer in locations not covered by plate. German gothic arming doublets were generally shorter than Italian white arming doublets, which could extend to the upper thigh. In late fifteenth century Italy this also became a civilian fashion. Men who were not knights wore arming doublets, probably because the garment suggested status and chivalry. 

Chainmail

Although commonly known as 'chain mail' or 'chainmail', the more correct term for this form of armour is just 'mail'. This protective garment consists of a large number of small interlocking metal rings, linked together to form a mesh. It was most widely used between the 3rd century BC and 14th century AD. A coat of mail can often be known as a hauberk or occasionally a byrnie. 

History

Some of the earliest surviving examples of thsi form of armour were found in the Carpathian Basin, buried in Horný Jatov, Slovakia. This was dated to be from circa 3rd century BC. The invention of mail is often attributed to the Celts, however there have been other examples found of the Etruscan pattern mail dating from even earlier,  at least the 4th century BC. This may have been inspired by the much earlier scale armour, which will be covered later in this work. 

Mail was widespread around the globe, ranging from places such as parts of north and west Africa, the Middle East, Central Asia, India, Tibet, South East Asia and Japan.

The ancient Greek historian, Herodotus, wrote that warriors of the ancient Persian Empire wore scale armour, but mail is also specifically mentioned in the ancient holy scripture of the Persian religion of Zoroastrianism, known as the Avesta. 

Mail continues to be used today as protective equipment in many industries including cut resistant gloves for butchers, woodworkers and some meat factory workers or as shark resistant wetsuits, plus many other applications.

Civilizations that used mail invented specific terms for each garment made from it. The standard terms for European mail armour derive from French: leggings are called chausses, a hood is a mail coif, and mittens, mitons. A mail collar hanging from a helmet is a camail or aventail. A shirt made from mail is a hauberk if knee-length and a haubergeon if mid-thigh length. A layer (or layers) of mail sandwiched between layers of fabric is called a jazerant.

A waist-length coat in medieval Europe was called a byrnie, although the exact construction of a byrnie is unclear, including whether it was constructed of mail or other armour types. Noting that the byrnie was the "most highly valued piece of armour" to the Carolingian soldier, Bennet, Bradbury, DeVries, Dickie, and Jestice indicate that:

'There is some dispute among historians as to what exactly constituted the Carolingian byrnie. Relying only on artistic and some literary sources because of the lack of archaeological examples, some believe that it was a heavy leather jacket with metal scales sewn onto it. It was also quite long, reaching below the hips and covering most of the arms. Other historians claim instead that the Carolingian byrnie was nothing more than a coat of mail, but longer and perhaps heavier than traditional early medieval mail. Without more certain evidence, this dispute will continue.'

European Mail Armour

The use of mail was very prevalent throught the Iron Age and Middle Ages, but lost popularity later one, during the 16th and 17th century due to plate becomming more widely produced. It is commonly believed that the Romans first encountered mail during their battles with the Gauls in what is now northern Italy. The forces of Rome adopted this new form of armour for the lorica hamata and during the Imperial period, this became their most common form of armour, taking over from the lorica segmentata that the Romans are more commonly known for.

After the fall of the Western Empire, much of the infrastructure needed to create plate armour diminished. Eventually the word "mail" came to be synonymous with armour. It was typically an extremely prized commodity, as it was expensive and time-consuming to produce and could mean the difference between life and death in a battle. Mail from dead combatants was frequently looted and was used by the new owner or sold for a lucrative price. As time went on and infrastructure improved, it came to be used by more soldiers. The oldest intact mail hauberk still in existence is thought to have been worn by Leopold III, Duke of Austria, who died in 1386 during the Battle of Sempach. Eventually with the rise of the lanced cavalry charge, impact warfare, and high-powered crossbows, mail came to be used as a secondary armour to plate for the mounted nobility.

By the 14th century, articulated plate armour was commonly used to supplement mail. Eventually mail was supplanted by plate for the most part, as it provided greater protection against windlass crossbows, bludgeoning weapons, and lance charges while maintaining most of the mobility of mail. However, it was still widely used by many soldiers as well as brigandines and padded jacks. These three types of armour made up the bulk of the equipment used by soldiers, with mail being the most expensive. It was sometimes more expensive than plate armour. Mail typically persisted longer in less technologically advanced areas such as Eastern Europe but was in use throughout Europe into the 16th century.

During the late 19th and early 20th century, mail was used as a material for bulletproof vests, most notably by the Wilkinson Sword Company. Results were unsatisfactory; Wilkinson mail worn by the Khedive of Egypt's regiment of "Iron Men" was manufactured from split rings which proved to be too brittle, and the rings would fragment when struck by bullets and aggravate the injury. The riveted mail armour worn by the opposing Sudanese Madhists did not have the same problem but also proved to be relatively useless against the firearms of British forces at the battle of Omdurman. During World War I, Wilkinson Sword transitioned from mail to a lamellar design which was the precursor to the flak jacket.

Also during World War I, a mail fringe, designed by Captain Cruise of the British Infantry, was added to helmets to protect the face. This proved unpopular with soldiers, in spite of being proven to defend against a three-ounce (100 g) shrapnel round fired at a distance of one hundred yards (91 m). A protective face mask or splatter mask had a mail veil and was used by early tank crews as a measure against flying steel fragments (spalling) inside the vehicle.

West Asia, India and China

Mail was also commonly used for protercting horsesfor cataphracts and heavy cavalry in addition to the soldiers themselves. Asian mail could weight the same as the European variety and occasionally they would have prayer symbols attached to the rings. This was both as a sign of their craftsmanship and an attempt at divine protection. Mail armour is even mentioned in the Quran as a present given from Allah to David:

21:80 It was We Who taught him the making of coats of mail for your benefit, to guard you from each other's violence: will ye then be grateful? (Yusuf Ali's translation)

From the time of the Abbasid Caliphate mail was quickly adopted in Central Asia by Timur (Tamerlane) and the Sogdians and by India's Delhi Sultanate. Mail armour was introduced by the Turks in late 12th century and commonly used by Turk and the Mughal and Suri armies where it eventually became the armour of choice in India. Indian mail was constructed with alternating rows of solid links and round riveted links and it was often integrated with plate protection (mail and plate armour). Mail and plate armour was commonly used in India until the Battle of Plassey by the Nawabs of Bengal and the subsequent British conquest of the sub-continent.

The Ottoman Empire and the other Islamic Gunpodwer Empires used mail armour as well as mail and plate armour, and it was used in their armies until the 18th century by heavy cavalry and elite units such as the Janissaries. They spread its use into North Africa where it was adopted by Mamluk Egyptians and the Sudanese who produced it until the early 20th century. Ottoman mail was constructed with alternating rows of solid links and round riveted links. The Persians used mail armour as well as mail and plate armour. Persian mail and Ottoman mail were often quite similar in appearance.

Mail was introduced to China when its allies in Central Asia paid tribute to the Tang Emperor in 718 by giving him a coat of "link armour" assumed to be mail. China first encountered the armour in 384 when its allies in the nation of Kuchi arrived wearing "armour similar to chains". Once in China, mail was imported but was not produced widely. Due to its flexibility, comfort, and rarity, it was typically the armour of high-ranking guards and those who could afford the exotic import (to show off their social status) rather than the armour of the rank and file, who used more common brigandine, scale, and lamellar types. However, it was one of the few military products that China imported from foreigners. Mail spread to Korea slightly later where it was imported as the armour of imperial guards and generals

Japanese Mail Armour

In Japan mail is known as a 'kusari', which in Japanese means 'chain'. When this word is used in conjunction with armour it normally means that mail constitutes the majority of the suit of armour. An example of this would be kusari gusoku which means chain armour. Kusari jackets, hoods, gloves, vests, shin, shoulder, thigh guards, and other armoured clothing were produced, even kusari tabi socks.

Kusari was used in samurai armour at least from the time of the Mongol invasion (1270s) but particularly from the Nambokucho Period (1336–1392). The Japanese used many different weave methods including a square 4-in-1 pattern (so gusari), a hexagonal 6-in-1 pattern (hana gusari) and a European 4-in-1 (nanban gusari).The rings of Japanese mail were much smaller than their European counterparts; they would be used in patches to link together plates and to drape over vulnerable areas such as the armpits.

Effectiveness

Mail armour was effective at defending against slashing blows by edged weapons, like swords, daggers etc, and some forms of penetration by many thrusting and piercing weapons. In fact, a study conducted at the Royal Armouries at Leeds concluded that "it is almost impossible to penetrate using any conventional medieval weapon". Generally speaking, mail's resistance to weapons is determined by four factors: linkage type (riveted, butted, or welded), material used (iron versus bronze or steel), weave density (a tighter weave needs a thinner weapon to surpass), and ring thickness (generally ranging from 18 to 14 gauge (1.02–1.63 mm diameter) wire in most examples). Mail, if a warrior could afford it, provided a significant advantage when combined with competent fighting techniques.

When the mail was not riveted, a thrust from most sharp weapons could penetrate it. However, when mail was riveted, only a strong well-placed thrust from certain spears, or thin or dedicated mail-piercing swords like the estoc could penetrate, and a poleaxe or halberd blow could break through the armour. Strong projectile weapons such as stronger self bows, recurve bows, and crossbows could also penetrate riveted mail. Some evidence indicates that during armoured combat, the intention was to actually get around the armour rather than through it—according to a study of skeletons found in Visby, Sweden, a majority of the skeletons showed wounds on less well protected legs. Although mail was a formidable protection, due to longswords getting more tapered as time progressed, mail worn under plate armour (and stand-alone mail as well) could be penetrated by the conventional weaponry of another knight.

The flexibility of mail meant that a blow would often injure the wearer, potentially causing serious bruising or fractures, and it was a poor defence against head trauma. Mail-clad warriors typically wore separate rigid helms over their mail coifs for head protection. Likewise, blunt weapons such as maces and warhammers could harm the wearer by their impact without penetrating the armour; usually a soft armour, such as gambeson, was worn under the hauberk. Medieval surgeons were very well capable of setting and caring for bone fractures resulting from blunt weapons. With the poor understanding of hygiene, however, cuts that could get infected were much more of a problem. Thus mail armour proved to be sufficient protection in most situations.

Plate armour

This is a historical type of personal body armour made from bronze, iron or steel plates, culminating in the iconic suit of armour entirely encasing the wearer. While there are early predecessors such as the Roman-era lorica segmentata, full plate armour developed in Europe during the Late Middle Ages, especially in the context of the Hundred Years' War, from the coat of plates worn over mail suits during the 14th century.

In Europe, plate armour reached its peak in the late 15th and early 16th centuries. The full suit of armour, also referred to as a panoply, is thus a feature of the very end of the Middle Ages and of the Renaissance period. Its popular association with the "medieval knight” is due to the specialised jousting armour which developed in the 16th century.

Full suits of Gothic plate armour were worn on the battlefields of the Burgundian and Italian Wars. The most heavily armoured troops of the period were heavy cavalry, such as the gendarmes and early cuirassiers, but the infantry troops of the Swiss mercenaries and the Landsknechts also took to wearing lighter suits of "three quarters" munition armour, leaving the lower legs unprotected.

The use of plate armour declined in the 17th century, but it remained common both among the nobility and for the cuirassiers throughout the European wars of religion. After 1650, plate armour was mostly reduced to the simple breastplate (cuirass) worn by cuirassiers. This was due to the development of the flintlock musket, which could penetrate armour at a considerable distance. For infantry, the breastplate gained renewed importance with the development of shrapnel in the late Napoleonic wars. The use of steel plates sewn into flak jackets dates to World War II, replaced by more modern materials such as fibre-reinforced plastic since the 1950s.