use of onagers and other heavy artillery

[Conqueror]

I usually use 2 onager per army, 4 if I'm going to assault a city. There are some specific exceptions though: in my current Seleucid campaign I have two full armies that have 8 onagers each. These armies I have stationed to guard the bridges of the Danube river, north of Tylis and Bylazora. They see alot of action since the Scythian hordes are hell bent to invade the southern Balkans and they keep attacking the bridges almost every turn.

I use 4 phalanx units to block the bridge, 8 onagers, 2 cataphracts (for chasing routers) and the rest of my units are archers. When the Scythians come, their archer warbands and HA will be eliminated by my onagers and archers, while their nobles impale themselves in my phalanx. 8 onagers means 16 flaming shots fired each "round" which is pretty much guaranteed to hit some units, if not the intended target

[Somebody Else]

I like scorpions... with RTR, there's enough per unit to make it worthwhile, and being able to reach ot and touch the enemy from so far away isn't so bad... Plus, when used in sieges, they don't damage my property before I can take hold of it. Excellent when going up against slow armoured enemy armies... or if there's a bridge or something. Also good for encouraging them off of hills.

[NihilisticCow]

I tend to use onagers in multiplayer as they are very useful in a stand off situation where neither side wants to attack. So the side with the artillery dominance tends to be the one defending, but they will be rather outnumbered by the other player (and the onagers won't generally kill enough to justify their cost if the enemy attacks), so everything should be balanced.
Scorpions also have a use versus heavy armour, e.g. Roman factions, where they are more effective than any archer.

In single player, frankly you can use whatever units you want and you'll probably win.

[Mikeus Caesar]

If i get later into games, where nearly everyone has Stone Walls of some sort, then my armies carry around 2 heavy onagers each, or if they can't have heavy onagers, they carry normal onagers.

[Wishazu]

you can use onagers very effectively to drive opponents off of strong defensive positions as someone else pointed out allready, this works equally well for multiplay and sp. i disagree that onagers are too accurate, they are only accurate at all when firing stone boulders, and these will only kill 1 or 2 men with a direct hit, in order to score any substantial kills you need to use flaming ammo and that is wildly inaccurate, a smart enemy will close with you before any random hits mess up his lines.

[Viking]

In single player, frankly you can use whatever units you want and you'll probably win.

That`s true, so when I use onagers, I use them `cause their fun.
But if I meet units that can run amok, then they thend to be useful.
Also as Aesculapius mentioned above, their extremely useful to kill generals with.

Today I used a unit of onagers to pepper my enemies while they were walking through my gates, and with one single shot, I killed more then 30 men!

[Marquis of Roland]

scorpions vs. repeating ballistas: which one is better?

[NihilisticCow]

scorpions vs. repeating ballistas: which one is better?

Depends on what's happening. Versus troops, if the enemy is advancing towards you, scorpions as they have a longer range so will cause more casualties. Repeating ballistas do have a faster fire rate than scorps, so I suppose a camped enemy would suffer quicker once in range, but I always find enemies never stay camped for long under these circumstances, so scorpions are better (the rate of fire is not that much less).

One thing though is that Scorpions do not damage fortifications or other siege weapons, whereas ballistas do, so it depends on what you want to use them for.

[SpencerH]

Properly used arty (mostly onagers in my case) are winners in open battle.

[Rodion Romanovich]

I usually use 2 onager per army, 4 if I'm going to assault a city. There are some specific exceptions though: in my current Seleucid campaign I have two full armies that have 8 onagers each. These armies I have stationed to guard the bridges of the Danube river, north of Tylis and Bylazora. They see alot of action since the Scythian hordes are hell bent to invade the southern Balkans and they keep attacking the bridges almost every turn.

I use 4 phalanx units to block the bridge, 8 onagers, 2 cataphracts (for chasing routers) and the rest of my units are archers. When the Scythians come, their archer warbands and HA will be eliminated by my onagers and archers, while their nobles impale themselves in my phalanx. 8 onagers means 16 flaming shots fired each "round" which is pretty much guaranteed to hit some units, if not the intended target

Yay, the 8 onagers in bridge battles are always lovely... I've done it many time in multiplayer - picking greece with 5-8 spartans, 1 cavalry, 8 onagers and the rest cretan archers... I usually get kill-death ratios like 20-1...

[Aesculapius]

In un-modded RTW, your unit size is surely an important determinant of how useful artillery is. As unit size increases, your number of artillery pieces stays the same - so the larger your unit size setting, the less valuable your artillery and the more fighting men you are 'giving up' by having an artillery unit in that slot. (I gather some mods increase artillery with unit size, which seems sensible.)

I usually play with 'small' or 'medium' units, and I love throwing rocks. My favourite RTW moment was facing an Egyptian army stuffed with chariots. My first throw - I kid you not, my very first - was greeted with the words "The enemy general is dead!" and the satisfying clip of a chariot being heavily crunched.

Of course, artillery does slow down your army's cross-country movement; but it does give you added flexibility in facing 'dangerous' units, attacking well-defended positions, and sieging at short notice.