Siege Damage
"When blocked during the combat phase, in addition to the battle damage to the combat target, also deal Siege damage to the enemy Tower."
- Artifact Tooltip
Siege damage is a damage type in Artifact
Siege damage cannot be blocked by units, allowing to damage the tower without getting past the unit in front of you.
Siege damage does not do anything if you attack the tower directly.
Artifact 2.0 Beta[edit]
Siege and Cleave has recieved the following changes:
"These damage types used to be dependent on the unit being blocked to function. Now they are active all of the time."