====== Protection ======
**Protection** is a property of units that reduces damage that they take from most attacks. It is generally provided from either manufactured armor or from natural protection (tough skin, scales, being made of stone, etc.) If a unit has both manufactured armor and natural protection, their values [[stacking effects#protection|stack with diminishing returns]].
Natural protection (NatProt) and armor protection (ArmorProt) combine according to the following formula:
==== Calculating Total Protection ====
$\text{Total Protection} = \text{NatProt} + \text{ArmorProt} - \frac{\text{NatProt}\times\text{ArmorProt}}{40}$
Since manufactured armor provides protection, the increasing technology level in Middle and Late Age means that most national and [[independent]] troops tend toward higher and higher protection values in later ages.
Whenever a unit is struck by something that might cause damage, the game calculates the damage dealt as follows:
==== Calculating Damage ====
$\text{Final damage} = \text{Damage} + \text{DRN} - (\text{Total Protection} + \text{DRN})$
where a final damage roll of zero or less doesn't do any damage at all.
Some attacks reduce the Protection of the target:
* //Piercing// damage only counts 80% of the target's Protection when calculating damage.
* //Armor piercing// (AP)attacks count only 50% of the target's Protection.
* //Piercing// and //Armor Piercing// damage stack multiplicatively, meaning that only 40% of target's Protection is considered when calculating damage.
* Some attacks are marked as //armor negating// (AN); these ignore the target's protection.
Note that magical attacks are not AN unless specifically noted. Typically fire attacks are AP; typically lightning attacks are AN.
==== Calculating Damage with Protection-reducing attacks ====
**Piercing:** $\text{Final damage} = \text{Damage} + \text{DRN} - (\text{Total Protection}\times0.8 + \text{DRN})$ \\ \\
**AP:** $\text{Final damage} = \text{Damage} + \text{DRN} - (\text{Total Protection}\times0.5 + \text{DRN})$ \\ \\
**Piercing + AP:** $\text{Final damage} = \text{Damage} + \text{DRN} - (\text{Total Protection}\times0.4 + \text{DRN})$ \\ \\
**AN:** $\text{Final damage} = \text{Damage} + \text{DRN} - \text{DRN}$
Protection is tracked separately for the head and body of units. Natural protection protects both locations; manufactured armor counts separately for each. For instance, chain mail protects the body but not the head, and a helmet protects the head but not the body.
Shields also have a protection value. If a unit has a shield, any hit to the shield results in the shield's protection value being added (without diminishing returns). In most cases this results in a final protection value high enough to completely negate the damage dealt, but not always.
===== Tactics =====
Protection amounts to a flat subtraction from the damage dealt by most attacks. High protection values can thus make a unit nearly immune to weak attacks, requiring a lucky DRN role to overcome; units with low protection values are vulnerable to large numbers of weak attacks, particularly arrows.
Various spells can boost units' protection; others can help you overcome targets with high protection.
==== Boosting protection ====
The ??Legions of Steel?? spell ([[Construction]] [[Research|3]], {{path>E3}}, 40 Fatigue) increases the Protection value of each piece of Armor worn by a large group of troops by 3.
Several [[Alteration]] spells increase the base Natural Protection of targets, but make them more vulnerable to certain sorts of magic:
* **Barkskin** increases Natural Protection to 10, or by +1 if it is already ten or higher, but confers 5 points of Fire Vulnerability. The ??Barkskin?? spell (Alteration 1, {{path>N1}}, 5 Fatigue) applies it to the caster, ??Protection?? (Alteration 3, {{path>N1}}, 20 Fatigue) applies it to troops in a single square, ??Wooden Warriors?? (Alteration 5, {{path>N2}}, 50 Fatigue) applies it to troops in five squares, and ??Mass Protection?? (Alteration 7, {{path>N3}}, 100 Fatigue and {{gems>1N}}) applies it to your whole army. There's also the Barkskin [[Bless]], which applies Barkskin to [[Sacred]] units when they're blessed, and requires {{path>N6}} in bless points during [[Pretender| Pretender design]].
* **Stoneskin** increases Natural Protection to 15, or by +2 if it is already 14 or higher, but confers 5 points of Cold Vulnerability. The ??Stoneskin?? spell (Alteration 2, {{path>E1}}, 10 Fatigue) applies it to the caster, while ??Marble Warriors?? (Alteration 7, {{path>E3}}, 100 Fatigue and {{gems>1E}}) applies it to troops in twenty-five squares.
* **Ironskin** increases Natural Protection to 20, or by +3 if it is already 18 or higher, but confers 5 points of Shock Vulnerability. The ??Ironskin?? spell (Alteration 3, {{path>E1}}, 20 Fatigue) applies it to the catser, ??Iron Warriors?? (Alteration 5, {{path>E2}}, 40 Fatigue) applies it to troops in a single square, and ??Army of Gold?? and ??Army of Lead?? (Alteration 9, {{path>E5}}, 300 Fatigue and {{gems>3E}}) apply it to your whole army; Army of Gold also applies 5 points of Fire Resistance, while Army of Lead boosts Magic Resistances by 4 instead.
These three effects do not [[stacking-effects|stack]]; only whatever was applied most-recently has an effect.
==== Dealing with high protection ====
One option for dealing with high protection units is to simply hit them harder; many nations have or can summon troops with two-handed weapons who are good at this. Many forged weapons provide very high damage values and/or AP or AN attacks; these can be useful in breaking through exceptionally high protection values on immobile pretender gods and some [[supercombatants]]. The most accessible of these is ??Greatsword of Sharpness??.
The spell ??Strength of Giants?? (Enchantment 3; Earth 3, 40 fatigue) grants +4 strength to a large number of troops, which can make an enormous difference in their ability to crack through well-armored enemies.
The spell ??Weapons of Sharpness?? (Construction 7; Earth 5, 20 fatigue) grants a large number of troops armor-piercing attacks. This is extremely effective against well-armored targets.
Troops with heavy armor tend to accumulate [[fatigue]] in extended engagements, which makes them more vulnerable to ??critical hits??. Swarming them with summoned skeletons or bugs from ??Swarm?? will eventually fatigue them out.
Finally, many spells bypass armor partially or totally. Air evocations can do large amounts of AN damage, and Death and Astral spells like ??Shadow Blast?? and ??Soul Slay?? ignore armor but allow for a [[Magic Resistance]] check.
{{tag>Combat-Mechanics}}