Useful Videos

Here are some things to think about.
The following is a list of videos that I have found to be interesting and useful when thinking about weapons and armor, and roleplaying in general. Most are about combat, and how different weapons have different uses, strengths, and weaknesses, and how different types of armor protect against different kinds of attacks. Some are about castles, some are about clothing.
They are a treasure trove of very useful information about history, technology, and techniques. I strongly urge anyone even slightly interested in any of this stuff to watch them.
Velyri (including the continent of Endrica) is not medieval Earth. There are similarities, and the physics works the same, except for that mana overlay that allows magic to work. But most of it is applicable, and may be worth thinking about. These videos have certainly modified the way I think about worldbuilding, and this world in particular.
If you are time-limited, and can only watch a few videos, I would suggest the "Arrows Vs Armor" videos, by Tod's Workshop. They can be found below under "Medieval Mythbusting".

Castles, and Life in General

Castle Building

Building A Castle Using 13th Century Tools | Secrets of the Castle | Absolute History

Here is a video on the decorated interiors of castles. And no, most interiors were not just stone, they were very colorful. Shad has updated the video, due to some things he's learned when it was pointed out that he got some things wrong.

Parts of a Castle

Names and terms of a medieval CASTLE's parts (Shadiversity)

Clothing

Most common types of MEDIEVAL CLOTHES or garments: MEDIEVAL MISCONCEPTIONS (Shadiversity)
REAL medieval men WORE DRESSES! but could you fight in them? MEDIEVAL MISCONCEPTIONS (Shadiversity)
Worldbuilding: Should your Fantasy Race Wear Corsets? An Intro to Corsetry (Mariah Pattie)
Medieval Historybounding: Designing a (Modern/Medieval) Capsule Wardrobe Based on Historical Fashion (Mariah Pattie)
Worldbuilding: Cultural Impact of Biology (Mariah Pattie)
An interesting video on the process of how flax gets turned into linen. It's quite time consuming and complicated. Textile armors are usually made of linen; both linothorax and gambeson fall into this category.

Elven Economics

Here is an interesting video on Tolkien's Elves and their basic lifestyle. While it is specific to Middle Earth, a lot of it is still relevant. Most of the Elves on Velyri live in small, mostly communal villages, where everyone knows everyone else, and effectively are like a large, extended family. Food is plentiful, as their inherent magics (the Hedge Magic) and deep knowledge of biology aid them much like the soil in Lothlorien does for the Shire.

Dwarven Economics

Like the Elven Economic video above, this one specifically goes into the economy of Tolkien's Dwarves. Again, it's specific to Middle Earth, there are still some things about the Dwarven mindset of Velyri's Dwarves that are relevant. The desire for trade, and relationships with other races, for example. There are some differences, however. Velyrian Dwarves have access to the Sunlight spell, which enables them to have caves devoted to agriculture. They also have small surface settlements in the mountains that allow for shepherding and some agriculture as well as a bit of hunting. Despite this, they still try to set up trade relationships with others, to get things they can't or won't provide themselves, and because trade is part of the nature of their culture.

Armor

Maille (Chainmail)

The Truth About Chainmail (Shadiversity)
Something About Maille Armour (Scholagladiatoria)
Introduction to mail (chainmail) armour (Scholagladiatoria)
A short article by Eric Lowe about maille.
Another article by Eric Lowe on how swords work against different armor types.

Gambeson

The TRUTH about padded and leather armor (Gambeson / Aketon) (Shadiversity)
Why padded armor (gambeson) is WAY better than leather armor (Shadiversity)

Plate

The TRUTH about full plate armor (Shadiversity)
Mounted knights, and putting armor on (Scholagladiatoria)Armor for being on horseback was not the same as "on foot" armor. Insides of legs and butt were not armored; this was because you need to feel the horse beneath you in order to control it properly, and having the insides of the legs armored would make you not able to do this.
How invulnerable were you in armor?(Scholagladiatoria)
Can you stab through plate armor? (Scholagladiatoria)
A good little short film demonstrating how good armor actually was, called "The Knight of Hope".
Various things to think about when wearing plate harness (Modern History TV)
Here is an overview of different types of plate armor decoration.

Leather

Was I wrong about medieval leather armor? Responding to my critics (Shadiversity)
Leather Armour - Historical or Fantasy? (Metatron)

Brigandine

Armor Review: Armstreet Brigandine - The Common Man's Plate (Skallagrim)
Brigandines & common soldiers' armour of the 15th century (Scholagladiatoria)
Brigandine Overview and a beautiful example of one, with pauldrons and bracers (Shadiversity)
Brigandines in general
More general info about brigandines (Metatron)

Armor in General

Medieval Battlefield Sword Fighting Vs Regular HEMA Sparring (Scholagladiatoria)
Medieval armour: what types were used in history? (Modern History TV)
Notes about Roman gladiators and their armor. Shows how protective their armor was, especially the scutum. (Scholagladiatoria)
Not a video, but a Quora article by Eric Lowe. It does a really good job about giving an overview about armor and how armor works.
Metatron has a good video on stealth and armor. The takeaway is with care, you can be at least somewhat stealthy in any armor, but basically, plate armor is the loudest due to the articulated plates banging against each other. Can You Be Stealthy in Armor?
An examination of Gaps in Armor in medieval artwork.
Examples of plate, mail, gambeson, and jack chains, on a liveried soldier. (The History Squad)

In the cold

What's it like to wear armour in the freezing cold and snow? (Modern History TV)

In the Heat

Heat Exhaustion: Can heat kill you in medieval armour? (We find out, it wasn't nice!) (Modern History TV)
Dash Rendar spent about two hours in his armor in 110 degree heat to see how it was. It was miserable; his average heart rate was 148bpm, spiking to over 175 when he had his helmet on. And all he did were some sword strikes on water bottles. He lost 8 lbs of water weight during those two hours. You can see the video here.

Knighthood

What Does It Mean to be a Knight? (Modern history TV) This is actually the first in a series of videos about medieval knights.

Weapons

Archery

Lars Andersen

Lars Andersen: A new level of archery
Lars Andersen reveals the TRUTH about the most viewed archery video ever made
Reinventing the fastest forgotten archery
Archery In the upcoming Robin Hood Movie

Medieval Mythbusting

ARROWS vs ARMOUR - Medieval Myth Busting (Tod's Workshop)Joe Gibbs fires some historically accurate arrows at a historically accurate breastplate using a Mary Rose style bow with a draw weight of 160lbs.
Tod's Workshop has done a second set of "Arrows Vs Armor" videos, this time with a more complete set of armor. Due to the success of the kickstarter that funded this, he also has several other videos focusing on more specific parts of the tests. Mail Tests. Arrowhead Material. Armor Plate Tests. Warbow Draw Weights. Armor Defeated! (Sort of).
Arrowhead smithing, specifically, plate-cutting bodkin points (Tod's Workshop). This is the guy that will be making the arrowheads (and the arrows) for the upcoming "Medieval Mythbusting 2" videos.

Notes on Medieval Mythbusting

Can Arrows Beat Armor? (Scholagladiatoria)
The best BOW vs ARMOR test I've ever seen, a response (Shadiversity)

Archery vs Armor

Archery vs Armor: The Importance of Arrows in Penetration Tests (Scholagladiatoria)
English longbows vs medieval plate armour - Battlefield Detectives documentary review (Scholagladiatoria)
Sharpened arrowheads vs. Gambeson armor (Tod's Workshop and the Lockdown Longbow)
Good video by Tod's Workshop on arrows vs. mail and gambeson
Arrows vs gambeson and mail, using an 87lb warbow and various arrow types and weights, which really shows how important how the weight of the arrow matters.

General

Doing the IMPOSSIBLE in MEDIEVAL ARCHERY, with Lars Andersen: longbow / warbow (Shadiversity)
Modern vs Historical Archery (Shadiversity)

Secrets of the Medieval Longbow / Warbow: MEDIEVAL MISCONCEPTIONS (Shadiversity)
Best medieval weapons for a fantasy warrior(Shadiversity) Fantasy Rearmed, weapons and warriors in general.
Matt Easton of Scholagladiatoria has a good video on medieval fantasy loadouts, encumbrance, and things to think about.
Shad does some testing on different postures while using a war bow. Can you SHOOT A BOW FROM A TREE like an ELF or RANGER?
Types of medieval arrowheads, from Tod's Workshop. Also shows how barbed arrows can be removed "safely". In general, there are three types of arrowheads that will be commonly used in the game: "standard" heads (broadhead, or the barbed war arrowhead), bodkin (for rigid armors), and needle bodkin (for flexible armors like mail and gambeson). The other hunting types are available, if anyone wants to use them (presumably for hunting). Those three would be the leaf-bladed heads, the swallowtail heads (horrible at longer ranges as they have the annoying habit of curving around in random directions because those large vanes act as wings), and the crescent headed arrows (presumably used for small game when you don't want to lose the arrows if you miss). If necessary, I will make up some rules for the hunting heads, but that hasn't been necessary yet.
Here is a nice video about broken arrows and field repairs, giving some data on whether pieces of broken arrows could be spliced together to give archers "one more shot." (The Fateful Force)
A video about field archery, which is a very different beast from straight up "shooting at a target".
Here is a video about how arrows are made during the medieval period: Hand Making a Medieval Style Arrow
Another video about arrows, this time showing the 10 basic types. (Tod's Workshop, with Will Sherman).
An interesting video by Matt Easton (Scholagladiatoria) about the pros and cons of various pole weapons. Basically, the Tondene hooked spear is a bill hook.
Tod's Workshop did a good overview of crossbow recocking methods.
Latchet crossbow and the Adder (a repeating, magazine-fed crossbow designed by Joerg Sprave). The video also shows several types of recocking mechanisms. Another video about the latchet crossbow.
Matt Easton (Scholagladiatoria) goes over "Left Hand Daggers" (aka "Main Gauche") in this video.
An extremely useful comparison of the various ways to draw a bow, what it looks like, and the differences between archery for speed vs archery for strength: Bluminek's Olympic Archer vs Historical Techniques.
Here is a good video about the different draw styles when using a bow.

Instant Legolas (magazine for bows)

"Instant Legolas" - Archery Reinvented (Jeorg Sprave)
The ULTIMATE medieval LONGBOW / WARBOW invention, the Instant Legolas (SIL) TESTED TO ITS LIMIT!! (Shadiversity)
Shut up now, critics! Medieval Instant Legolas (Joerg Sprave)
The Last Instant Legolas Video? (Joerg Sprave) It's not.
Joerg: What was he thinking? (Tod's Workshop)
The rapid fire bow, my thoughts on the Instant Legolas FANTASY RE-ARMED (Shadiversity)
Could this device have changed medieval European history? (Modern History TV)
Tod's Workshop builds an Instant Legolas medieval-style (Tod's Workshop)It has a nice bit at the end where he shows 5 archers firing a volley (via tha magic of editing Joe Gibbs x5)
https://www.youtube.com/watch?v=2m3QK2W0oms Shad tests Tod's SIL with his 70lb and 100lb bows (speed comparison of SIL vs warbow) (Shadiversity)

Spears

How To Use A Spear - Part 1, Changing Grip (Scholagladiatoria)
Spears: Why they defeat swords, optimum characteristics & perfect length (Scholagladiatoria)
Underappreciated Historical Weapons: the SPEAR (Shadiversity)
Spears are better than swords (longer version)
Things to think about when lugging around pole weapons.

Other

Wastewater treatment (sort of a starting point for the Elven rinqualastë).
Matt Easton of Scholagladiatoria has a good video about poleaxes.
A good overview of dagger types: Quillon, Basilard, Bollocks, Rondel. (Scholagladiatoria)
A "piercing" test of Tod Cutler's historical reproduction of a rondel dagger from the Wallace collection. It's really, really effective against cloth, maille, and even 1.2mm mild steel plate. Video And Matt Easton's (Scholagladiatoria) additional follow-up video.
And for something completely different, here is a video on a type of food preservation called "potting", from Townsends. Which, although being focused on the 18th century, still has a lot of good information for older periods, because the techniques used in the 1700's had been developed earlier.
Here is a video on medieval toilet habits, gob (or gong) farmers, and what uses human waste was put to. (Modern History TV)
Bushcraft: Skills for the frontier (Survival skills). Things like making shelter, using blankets as clothing, making cordage, starting fires, setting up cooking systems, and rendering fat to use as a waterproofing and moisturizing material. Interesting stuff. (Townsends)
Interesting video on saddling a horse while in a hurry (Modern History TV). He uses a medieval saddle, and also sees how fast he can get a horse ready (like when you haven't paid the tavern bill, and want to get out of town fast).
Fast food, medieval style (Modern History TV).
This is a video on bushcraft shelters, using an oilcloth tarp. (Coalcracker Bushcraft)
And now for something completely different: Human attempts at Elven architecture styles! Baubotanik buildings using trees.
Here is a video about food preservation methods before the age of refrigeration and modern preservation methods. (Townsends)
Hobbiton in New Zealand has been expanded, and made permanent (the original sets weren't designed to last very long). Here is a video of a one of one of the residences, showing a "typical, traditional" middle to upper class home.
Townsends has a good video about building a spit-jack (clockwork rotisserie, basically).