Artillery is a revolutionary new feature added to the mod in v4.0. There's currently only field artillery and there are no plans to add siege artillery. Artillery exist as field cannons only.
To properly use cannons in battles, you'll need at least:
- Cannons (goods merchant; put into your inventory)
- Cannonballs (weapons merchant; put into your inventory)
- Gunpowder (weapons merchant; put into your inventory)
- Cannoneers (2 per cannon) (taverns)
Artillery is very expensive and requires a solid financial base. Revolutionary is the way how cannonballs use true ballistics, similar to Napoleonic Warfare. This way it's recommended to not use cannons in mountainous areas.
You can use up to 6 cannons in one battle just equal to your opponent. AI lords use artillery as well, though they are rare. Kings tend to have more cannons. The King of the Rhodoks is an especially famous fan of artillery. He can bring 6 cannons into one battle if you're unlucky.
In battle cannoneers will find an eligible opponent to fire at. They'll aim on the ground just before the enemy troops. Cannonballs will always bounce one time and land way further, causing terror to all troops between.
Select Artillery group with 4 (not numpad). Use F1 to manually set a target (place a flag on the battlefiled) to fire on. Now your cannoneers will shoot at this position. Don't aim on the ground before the enemy troops as cannoneers are perfectly capable to do this themselves. Warband functions such as 'hold fire' and 'charge' can be used to stop/continue shooting. Do this to prevent friendly fire.
Cannoneers are mercenaries and can be upgraded 2x, to 'Skilled Cannoneers' and further to 'Experienced Cannoneers'. They'll load the cannons much faster.
Cannons spawn with stakes for defence against cavalry.
You can manually fire cannons. Take control by interacting with the cannon (aim at the barrel and hold down F to manually fire it) . Beware you cannot undo this. Use arrow keys to aim (set angle) the cannon barrel and load it. Interact with the cannon (press F) again to fire it.
You can adjust the settings for artillery at the camp menu -> options. You can completely disable artillery or adjust the spawn rate.