From The Heroes of Might and Magic III wiki
Arrow towers are special addition to combat when hero is trying to capture a garrisoned town.
- All shooters of all towns do the same damage
- If Fort, Citadel and Castle is built the Base Damage is 15 for the Keep, and approx. the half of it for the other shooters.
- Every Building (dwellings, marketplace etc.) increase the damage of the Keep by 3, which means approx. 6 more damage per round (3 +1,5 +1,5).
- Dwelling and Mage Guild upgrades do not increase the damage.
- Although there is a range given (rightclick on Keep) it will almost always do the max. Damage (sometimes +1 or 2 points)
- It doesn't matter what is the target, the damage will be the same no matter what.
- Secondary Skills, Artifacts etc. (especially Archery or Artillery) don't have influence to the damage.
Formula for total damage per round: (Keep + Buildings * 3) *2
Defending heroes with the Artillery skill will be able to control the Arrow Towers
- Heroes with Armorer skill take additional damage (approx. double).
- Creatures with Air Shield take additional damage (same as above).
These bugs have been fixed in Horn of the Abyss.