This feature is a work in progress.
At the moment bombs can be placed with
/bomb and trebuchets with
Bombs are cheap siege devices allowing most infantry to contribute to a siege by damaging key locations. Bombs require a very small area to deploy, but also only do moderate damage.
Trebuchets are the most expensive siege weaponry you can build, but in the right hands can deal devastating damage at incredible ranges. Trebuchets require a large area and number of resources to deploy.