Ballistas - useless?

[Chelifer]

Probably the epic stairs are not wide enough :)

[Sam Adams]

the only time I use artillery from the field is when fighting enemy horse archers, chariots, or elephants. Basically the things that can only be effectively killed at range.

usually your own archers are more effective though, except against elephants.

[mfberg]

I was carrying two ballista units in my army against the gauls, they helped in an open field battle, not as much as an archer aux. would have, but in a later bridge battle they paid for themselves.

mfberg

[Alexei]

And actually what were they historically designed for?

[Darius]

They were designed both for seige defensive uses and offensive uses, though I do know one general used them in a field battle in Asia Minor once. Might have started a precedent, but maybe not.

[Oaty]

And actually what were they historically designed for?

Breaking formations and reducing morale, provoke a charge so the Romans would not have as far to march to meet there enemies.