One of the important problems in AOW is defending your cities. I have noticed that fortifying is a very good answer at the earliest stages, when no flyers are available yet, and that it is very effective to put archers inside to shoot the attackers attempting to breach the walls.
Basically, I can just ignore any units besides ranged ones for this purpose, but I thought about using a ballista, or a few of them.
A ballista costs 72 gold to produce and the same to install, and 6 for upkeep. An archer costs 15 gold to produce, does not need to be installed, and 4 for upkeep, so one ballista costs almost 7 times more to produce, and, more importantly, 1.5 times more for upkeep.
But the Shoot Javelin Ability deals around 2.5 times more damage than Archery, and from around 2 to 2.5 times more than Archery with Marksmanship I, and, what's also important, is long-ranged, so I always have the first shot. So, if I want to have the same firepower and buy two ballistae, I have to pay 144 gold instead of 75 gold for 5 archers, and pay 12 gold upkeep per turn for two ballistae instead of 20 for 5 archers. So, I pay 69 more gold for producing, and save 8 each turn: after 9 turns ballistae turn out to be cheaper. 5 archers also take 5 turns to produce in a two-hex city, while ballistae take 4 turns to produce two of them, which means losing income from Producing Merchandize for 1 turn in the case of archers.
Another option would be installing ballistae exactly where I need them. A two-hex city is needed for that, with 4 turns for production and 1 turn for installation, 5 turns all together. Same time would be needed for 5 archers. The archers cost 75 gold, ballistae cost 216 to install and produce two, or 141 more gold, which means ballistae being more effective money-wise after 18 turns.
I would like to hear some advice from proficient players: are ballistae better or worse than archers for protecting walled cities?
Best Answer
Ballistae are better at protecting cities, especially against higher tier creatures.
Archery has an Attack 4, while Shoot Javelin has 5, that's already a nice boost to the hit chance, especially against creatures with high Defence.
The ballistae higher range (12) allows it to attack 2-3 times before the enemy is upon them. Archers with their range of 8 only get 1-2 before being overwhelmed.
Without Marksmanship skill, a javelin deals up to 5 dmg, while an archery hit deals only 2. Even a single Shoot Javelin hit can already deal significant damage to most creatures compared to Archery, but Archery is also less likely to hit all of its attacks.
Against lower-tier attackers, archers and ballistae both do a good job, but even here 2 ballistae will handle things quicker than three archers. Against a heavy attack force, you are much more likely to inflict noticeable damage using ballistae, as archers will barely hit anything, and if they do, they only tickle.