When the elaborate fortifications make Catapults less and less effective at breaking them, it's time for a new invention. Utilizing the recently-developed gunpowder, renaissance engineers devise what is basically a giant musket which hurls giant metal balls with great speed against things.
The Bombard has little trouble blasting through the defenses of Renaissance-era cities and their districts. It also becomes available right after the Musketman, which is good at providing support for it on the battlefield. A couple of Bombards positioned on hills or flat land within firing range of a city will soon have it ripe for the taking. And its defensive strength is decent as well!
Siege units are not completely disallowed to move and shoot in the same turn until they earn Expert Crew promotion. In fact, in order to shoot, a siege unit is required to have 2 Movement left, meaning it can move and shoot in the same turn without Expert Crew if starting its turn next to a Great General or is used on Roads.
Civilopedia entry Edit
The oldest representation of a bombard – a muzzle-loading, smoothbore proto-mortar that was used to throw stone balls against fortifications during sieges – was found in China; the 12th Century AD Buddhist cave-sculpture depicts a demon firing one. In the Western world, English monarchs were certainly using them in the 14th Century, for Edward III had some at Crécy in 1346 and Henry V captured Harfleur using bombards in 1415. But with the largest weighing several tons and all notably inaccurate, bombards were not practical for field operations, soon enough being replaced by cannon; emplaced bombards, however, remained in use for centuries, usually protecting ports and sea passages. Among the last and largest, the Dardanelles Gun built by Munir Ali in 1464 weighted in at 16.8 tons and helped protect the straits for the Ottomans for a long, long time (being fired for the last time at a British fleet in 1807).