Many soldiers on the battlefield wear armor which may greatly increase their survival chances from eslewise a fatal strikes.
TT armor
If a model has equipped armor there is a chance for her to completely deflect wound. Such chance called Armor save throw and is calculated by comparing Armor save value of model with a 6-sided dice saving throw result. If Armor save throw result is equal or more of Armor save value then save is successful and model avoids being wounded
Armor save value is cumulative from different type of armor, i.e. light armor (6) + shield (6) will give armor save on dice throw of 5 or 6 (pls. see saving throw chart).
For example, an Elf has light armor and a shield. Elf armor save value is 5+ which means that in case of being hit and wounded Elf needs to make saving throw 5 or 6 to avoid the wound.
Armor save throw can be additionally modified by hit delivered with strength 4 or more (please, see the chart).
For example, if the same Elf in light armor with shield which give 5+ armor save value was hit by Orc with S4 then it will modify Elf saving throw result by -1, i.e. 5 - 1 = 4 and 6 - 1 = 5. This means that due to powerful strike of Orc, Elf needs to make saving throw with result 6 to avoid being wounded.
Heavily armored soldier is better protected and has better chances to survive. The downside of heavy armor is that soldier's movement is hindered and he gets penalty to his Movement characteristic.
DO armor
SoTHR developers decided to simplify TT rules and replaced Armor saves with Armor Rating (AR) equivalent (Pls. see the picture)
DO developers used the same approach and any model in the game has base AR from AR 0 (no armor) to AR 5 (full armor). Each one AR gives 16.6% chance to avoid wound, thus:
AR = 0 - 0%
AR = 1 - 16.6%
AR = 2 - 33.3%
AR = 3 - 50%
AR = 4 - 66.6%
AR = 5 - 83.3%
It is not possible to equip/unequip armor in DO and it is just unit parameter which can be modified by buying/selling additional armor piece in the game withing unit min, max AR limit.
For infantry the limit is AR 1-3. It can be additionally boosted by magic item such as magic shield to AR 4. For cavalry the limit is AR 2-5. The minimum AR is 2 because cavalry gets AR 1 for horse and AR 1 for barding.
Same as in TT, Armor rating can be decreased by Strength of the model that delivers hit starting from S4.
For example, Elf with AR 1 was hit by Orc with S4 (-1 modifier). Due to powerful strike of Ork Elf armor is disregarded as he has no armor save, i.e. 1 - 1 = 0
Armor and speed
DO playtest shown that GB cavalry unit has base speed equal to M7, while in TT horse has M8 value. Since GB cavalry has base 2 AR it may mean that DO devs intentionally decreased its speed to M7 to replicate TT armor penalty for horse with barding (Armor save 5+ which is equivalent of AR 2).
Armor save formula
can't be found in this page that describes melee combat
Strength of attacker => 4 decreases Armor Rating:
SOTHR armor
4thE armor
