The following types of damage are reduced by armor and, consequently, damage the armor itself:
- Direct attacks from mobs
- Direct attacks from other player
- Getting hit with an arrow
- Getting hit with a fireball from a Ghast or Blaze
- Touching a block of fire or lava
- Touching a cactus
- Explosions
The following types of damage are not reduced by armor and have no effect on the armor itself:
- Ongoing damage from being on fire
- Suffocating inside a block
- Drowning in water
- Starvation
- Fall damage
- Falling into the Void
- Poisoning; e.g., from a Cave spider attack or a Potion of Poison
- Instant damage from a Potion of Harming
- /kill command
Protection enchantments protect from types of damage that armor doesn't protect against without an enchantment, like falling damage. Armor durability still doesn't decrease when protection-enchanted armor takes environmental damage.
The following table shows the amount of defense points per units of material (i.e. the cost efficiency), compared with the chestplate of each material.
MaterialHelmetChestplateLeggingsBoots
Leather53%100%76%67%
Gold64%100%69%40%
Chain64%100%91%40%
Iron53%100%95%67%
Diamond60%100%86%75%
The following table shows the amount of defense points added by each individual piece of armor, as well as the total points added by a full set of armor for each material.
Each point of armor reduces the damage you take by 8%, up to the maximum reduction of 80%.*
MaterialFull setHelmetChestplateLeggingsBoots
Leather71321
Gold112531
Chain122541
Iron152652
Diamond203863
The following table shows the amount of damage each piece of armor can absorb before being destroyed.
Any "hit" dealt by a mob (including creeper explosions) will remove 2 durability points to the armor.
Other damage sources usually remove 3 durability points to the armor, except cacti (only one point).
Damage taken that armor doesn't protect (such as falling or drowning) will not damage the armor.
MaterialHelmetChestplateLeggingsBoots
Leather56817666
Gold7811310692
Chain166241226196
Iron166241226196
Diamond364529496430
The following tables shows the durability per unit of material of each piece of armor, compared to that of the boots. Note that the durability per unit does not depend on the material.
HelmetChestplateLeggingsBoots
durability/unit68%61%66%100%
This means that for the same number of leather/iron ingots/gold ingots/chain/diamond, boots can take 1,5 more damage than leggings.
Thus, chestplate and leggings offer more defense points per unit, but have a lesser durability per unit.
Armor can get protection enchantments such as "Protection III" or "Fire protection IV". The maximum level of a protection enchantment is IV (4). Protection enchantments stack (up to a cap). The type of protection enchantment determines whether the protection enchantment comes into effect, according to the following table:
EnchantmentDamage reduced for
ProtectionAll
Fire protectionFire, lava, and Blaze shots
Blast protectionExplosions
Projectile protectionArrows and Ghast/Blaze shots
Feather fallingFall damage (including ender pearls)
This means that "Protection" is always at least as good as for example "Fire protection", even against fire damage (with the exception of "Feather falling", see below).
The enchantment damage reduction is applied to the damage left after the armor's basic effect, and the base "enchantment protection factor" (EPF) of an enchanted item is
floor ( (6 + level * level) / 2 )
Which gives the following EPF for enchantments of level I-IV:
LevelEPF
I3
II5
III7
IV11
For Feather falling, the EPF of the specific piece is doubled.
The total EPF is the sum for all armor pieces, and capped at 25. An EPF of 25 can be reached by two level III pieces and one level IV piece (2*7+11=25). This also means that Feather Falling is unneccesary to reduce fall damage if you can reach an EPF of 25 without Feather falling boots.
The actual EPF applied is randomized to between 50% and 100% of the EPF calculated above, rounded up, and capped at 20. Each level of the actual EPF reduces damage by 4%, for a maximum damage reduction of 80% from enchantments. Since this is applied after the base armor damage reduction (80% for diamond), you get a total 89.6% to 96% damage reduction for a diamond armor set with an EPF of 25, for damage which is mitigated by unenchanted armor (fx fall damage is not mitigated by unenchanted armor).[2]
*-I'm paraphrasing since it is said in past tense else where what each defense point calculates into. Still accurate to the best of my knowledge.