A siege engine in Age of Medieval is not an effect. It is a unit with health, a crew and a job.
There are four. The ram goes for the gate. The trebuchet opens a breach in a stretch of wall from a distance. The siege tower rolls up and puts infantry on the wall-walk. The mantlet is a wheeled screen that covers the men advancing behind it.
Engines have to be built during the siege, before the assault, and they are slow. That gives the defender something to do: a ram destroyed on the way never touches the gate.
The other Houses build and use the same engines. If you see a lord camped outside a walled town for days, he is not idle.
Age of Medieval is developed by UnderStudio in UnderStudio 2D and published by Brasa Interactive. It releases on 17 May 2027.
Official site: https://ageofmedieval.com/