Armor in Elders Scrolls Online protects players from Damage sources, providing the player with Physical and Spell Resistance. Players can select from Light, Medium and Heavy armor pieces to fill their character's seven weighted armor slots. Each one has benefits and drawbacks due to the differing effects Armor Passive Skills and Champion Point stars which scale based on the number of pieces of each Armor weight equipped. Light, Heavy, and Medium armor have increasing resistance values in that order.
Donning a piece of Armor increases you Physical and Spell resistance. The ratio of the stated value of the Armor and the each resistance type it supplies is close to 1:1, but this is affected by Passive Skills, Champion Point Allocation, and other factors, and the actual calculation is more complex.
Players can customize the Style of Armor to reflect their choice of appearance, although this appearance will be hidden by their Outfit. Using a Style Motif on a certain character gives that specific character the ability to craft pieces of the specified type(s) in the specified style, but allows the use of that Outfit style account wide. A crafted piece of armor traded or sold to another player without that motif will retain its appearance, and that player can choose to show that piece (by not covering it) in their Outfit, and Dye it to any desired color combination with their unlocked Dyes.
One acquires rank in an Armor Skill line by simply wearing a piece of that type and gaining experience from any source. This is different than how previous games in the Elder Scrolls series worked, whereby, a player must actually be hit while wearing that armor type to increase experience in that line. Players can wear one of each type and simultaneously rank up all three types if they are so inclined. Equipping more than one piece of armor of a specific type does increase the speed in which you rank up that Armor Skill line.
Armor Sets can be crafted, dropped from enemies, found in chests across Tamriel and in PvP reward bags and vendors in Cyrodiil. A Blacksmithing Station is required and adequate training in Blacksmithing is necessary to create Heavy Armor, while a Clothier Station and adequate training in Clothier is required to make Medium and Light Armor. Highly skilled artisans can also upgrade Armor dropped from enemies.
Different Armor pieces can have different Traits and Glyphs attached to them when dropped by enemies or via crafting. They can also be crafted with set bonuses at unique Crafting Stations across Tamriel. For a full list of these and the locations of these Crafting Stations please see the Blacksmithing or Clothier pages.
Each Armor skill line has its own tree. These are Light Armor Skills, Medium Armor Skills and Heavy Armor Skills Each tree has 1 active skill and 5 passive skills to choose from. It is not required to put points in any of them to use armor of any type. All classes can use all types of armor by default.