Armor
The durability of your armor is a combination of the style of armor and its materials. Less durable materials like cloth and leather are comfortable, lightweight, and inexpensive but struggle to turn a hit. Metals may turn a hit more easily but require more physical strength to wear and cost more coin. The different styles of armor are outlined below.

When you are wearing armor that you aren’t proficient with, you have disadvantage on ability checks, attack rolls, and saving throws using Strength or Dexterity, and you are unable to cast spells.

Padded. Layers of cloth or supple leather are quilted together to create a lightweight tunic and pair of trousers. Padded cloth tunics are worn under breastplates and suits of mail for comfort and are already counted in their AC.

Brigandine. A tunic made of cloth, leather, or hide that has small panels of metal, scale, or bone stitched to the interior for extra protection. When the panels are external and overlap closely, the brigandine is termed scale mail. 

Breastplate. A fitted bone, leather, or metal plate that covers the chest, stomach, and vital organs. 

Mail. A suit made entirely of metal, though styles can differ greatly. A chain shirt is a shirt woven from small metal rings, while a full set of chain mail (a hauberk) is longer and includes a coif. Half plate covers most of the body in shaped metal plates, but offers minimal leg protection, while full plate covers the entire body and includes gauntlets, boots, and a helm. Splint mail is similar to half plate but covers the limbs in strips of mail bolted to leather, rather than shaped metal plates. 

Bulky Armor. Half plate and full plate are bulky, but while worn they do not count against the number of bulky items you can carry at once.

Strength Requirement. While wearing armor for which you do not have the minimum Strength score, your Speed is reduced by 10 feet.

Table: Light Armor

Table: Medium Armor

Table: Heavy Armor

Helms
Helms fit over your head to protect your skull, though in exchange they limit your vision and hearing. No proficiency is required to wear a helm.

Helm (12gp, 4lbs). This hard leather or metal covering protects the head but not the face, with the exception of a strip over the nose. While wearing this helm you gain a knack die on saving throws made to resist being stunned or rattled, and your passive Perception score is reduced by 2.

Visored Helm (25gp, 8 lbs). This helm covers the entirety of the head, including the face; the visor may be moved out of the way of the face as an object interaction, in which case the visored helm functions as a standard helm. While wearing a visored helm you gain a knack die on saving throws made to resist being charmed, stunned, or rattled, and your passive Perception score is reduced by 5. Additionally, whenever you take damage from falling, you reduce that damage by 5.

Donning, Doffing, Sizing, and Sleeping in Armor
Armor is typically fitted to its wearer. When you first acquire a set of armor, if it is nonmagical you must make or pay for alterations. Making the alterations yourself requires tool proficiencies as if you were repairing the armor. If the armor is not appropriately sized to you but is of your size category, you must make a DC 12 Constitution saving throw at the end of each day, acquiring a level of fatigue on a failure. You may alter armor that is a size category larger than you are, but you cannot fit into armor that is too small—a Medium human could trim down a morgant's breastplate, but could not resize a wolfcat's full plate to fit their larger form. 

It is assumed that cloth armor is worn under breastplates and suits of mail. Aside from cloth, leather, and hide, armor is too rigid and uncomfortable for a restful night’s sleep. If you sleep in medium or heavy armor other than hide, you are roughing it, you regain half the usual number of Hit Dice, and if you have any levels of fatigue or strife neither is reduced upon finishing the long rest.

Donning and Doffing Armor
The time it takes to don or doff armor depends on the armor’s category.

Don. This is the time it takes to put on armor. Your Armor Class is only increased by armor that you have fully donned.

Doff. This is the time it takes to take off armor. If you have help, reduce this time by half.

• Light Armor 1 minute/1 minute
• Medium Armor 5 minutes/1 minute
• Heavy Armor 10 minutes/5 minutes
• Shield 1 action/1 action