Basic Information
Full plate armour emerged in the late middle ages and early renaissance and consisted of a comprehensive and fully articulated set of plate armour. Expect every element of plate to be present, with gousets of mail wherever plate absolutely could not be fitted.
Unlike previous applications of plate, full plate was not just a layer but a fully integrated protection system. The majority of the work was done by the metal plates, which were custom fitted to the user and designed to work together as a whole, channeling attacks off the wearers body almost as much as they directly stopped them and directing a strike away from vulnerable areas when it could not be altogether deflected. The plates were worn over a padded layer - commonly known as an arming suit (or, more generally arming doublet and arming hose) - which provided impact protection, thermal insulation and generally made the armour more comfortable to wear. This layer was itself re-inforced by patches of mail, sewn onto it at points of particular vulnerability. Properly made, fitted and worn full plate should have offered very few points of vulnerability and presented a real obstacle to any contemporary weapon.
Contrary to popular legend, full plate was not especially heavy and the weight was fairly well distributed across the body - there are records of at least one constable of France showing off by doing gymnastic excercises in his full plate, including vaulting into the saddle. Granted, this was a man in superb physical condition and the fact that he was showing off implies that this was above what was normally possible, but a plate armoured knight (and later gendarme), was far from the beached whale that Victorian legend implies. There is also plenty of modern evidence of experimental archaeologists and holplologists performing similar saltatations in near facsimile replica suits - with practice, even a fairly average sort of person could move quite freely in full plate.
These legends seem to have two main sources - first the plate mail that preceeded full plate. This was horrendously encumbering, taking the already heavy and poorly distributed mass of mail and buckling additional metal plates onto it. This did have a genuine potential to keep a fallen man on the ground, and probably did present a significant obstacle to mounting a horse. The other source would seem to be jousting plate. To be fair, jousting plate was full plate armour - it just wasn't the sort of armour anyone wore into combat. It was, essentially, sports equipment and, as such, could make greater sacrifices of mobility, vision and dexterity in return for protection, given that the user would only be riding a horse at a target directly infront of him and was not generally prepared to gamble his life to do so. Jousting plate was thicker, and included much better joint protection (up to and including a great helm in many cases), but as a result was heavier and a lot less flexible. Add either or both of these to the fact that the historians test-wearing them had not been raised from a single digit age to wear armour and may have been wearing suits tailor made to fit other people and it is not entirely surprising that the legend should emerge.
On the subject of jousting plate, it is worth noting there was also a distinct tradition of building suits of full plate so that they could be used on the battlefield but were also upgradable for jousting (given that quite a few people couldn't afford two complete sets). There were two main ways of doing this - one was garniture: basically building the suit with a range of interchangable pieces so that you could swap out battlefield ones for jousting ones and vice versa as required. The other method consisted of fitting grand-guards to the battlefield suit - basically additional pieces of plate which would overlie the suit and provide additional protection, especially in the matter of covering weakspots.
The main disadvantage of full plate would appear to be the sort of fatigue and heat build up occasioned by prolonged use - the Battle of Towton (1461, War of the Roses) - was fought in the snow and still, apparently, had numerous examples of plate-armoured men collapsing with heat exhaustion.
Sources
Game and Story Use
- Most RPG systems fail to model any of the following appropriately:
- The huge improvement in protection from plate mail to full plate.
- The huge price of full plate, or its bespoke nature.
- The dexterity and mobility possible in full plate.
- In general, most systems simply level up in a fairly linear manner - a bit more protection, a somewhat higher price and a bit more encumberance. Some even preserve the immobilising plate legend.
- Even leaving aside the realities of medieval supply side economics, no-one should be able to buy this stuff on a walk-up basis. Even a second hand suit would require virtual re-building to work for anyone not a virtual twin of the original user and a bespoke suit of the wearer's own would need to be comissioned months in advance.
- It should be noted that this wasn't the sort of thing that any journeyman armourer could knock out - nor even many masters. There is apparently evidence of suits travelling across medieval Europe for specific customers - usually crafted to a full set of measurements and then detail fitted on arrival.