Posts from Penalty for shooting through castle walls.

"Will of Ash" - "Heart of Darkness" [2nd campaign, 5th mission].
I am storming the castle. For some unclear reason, when liches attack, the penalty is not 2 times (50%), but 4 times. However, for the hero inside the castle, higher-level liches are penalized only 2 times (50%) when they attack.

This is a feature of castle walls. Let's say you have forest archers (unit name) attacking a castle. Under normal circumstances, there would be no penalty at all. But when attacking a castle, the penalty will be 50%. The defending forest archers will not have a penalty! That is, the attacking side receives an additional penalty that is twice as high. This is not a bug. If you have the "Unicorn Horn Bow" artifact equipped, the penalty is further reduced by half. For example: for forest archers, it will be 25% (when attacking a castle), and for regular archers, it will be 50%. In addition, if you destroy the section of the wall through which your archers are shooting, the wall penalty is canceled. If you bring the archers into the castle, the penalty is canceled. Additionally, regarding the "Unicorn Horn Bow" - it is useless for archers (unit name) and forest archers. The damage under normal circumstances will be 100%, but not 200%.

Excerpt from the manual, explaining this issue.
In addition, walls protect defending troops from enemy archers. Damage from enemy ranged attacks
is reduced by half. If, in addition, a range penalty is applied to the attack, the damage will be
reduced by a total of four times.