What are your cheapest core units to defeat Rome?

[QuintusSertorius]

Not relevant...

[zenisar]

So I continued in my testing Arverni campaign in the meantime. The year is 230BC, I built 3 armies for deploying various units and see how they perform:
- a northern-gaul army - with units recruited north of the Alps,
- a southern-gaul army - with units recruited from Cisalpine Gaul,
- and a kelto-hellenic army - from units recruited from Massilia and maybe later Emporion as well.

But the Romani still did not get their Polybian reforms because they did not take Syracuse yet. It seems they use all their resources to attack Arverni in Cisalpine Gaul, sending army after army rather than finishing conquest of Sicily. This is how the composition of their armies frequently looks like:



While waiting for Polybian reforms I took Patavium as well, and plan to bottle Romans in Italy. Hopefully this does not contradict with the reform conditions. Busy with battles in northern Italy like this one:



While fighting in Liguria, one unit fighting for the enemy actually catched my attention: Gaemiae Liguariae. My general was better than theirs, my army outnumbered theirs, some quality units like Principes and Pedites were already in flight, while a unit of Ligurian infantry still held their line even when being surrounded from 3 sides. Actually, they were the last to rout:

[zenisar]

Because waiting for the Polybian reforms takes ages and I am concerned when and if it will ever happen, I became curious with another question. See, originally I wanted to "assimilate" whole Europe and make it a nice green natural area of Celts living in their villages in harmony with nature ... environmentally friendly ... ecologic ... whatever ... BUT as the Celts miss the highest level of cities, it shortens their time and forces to rush. Otherwise, some huge cities like Roma will build level 4 government building after reaching 12.000 population limit and their Roman culture cannot be overrun anymore in game. So I became obsessed with questions like:
- How can I prevent it?
- Do I have to conquer Rome?
- When can I conquer Rome the earliest?

So I set on another campaign, forking the current one just after defeating Aedui in Gaul, and started MARCH ON ROME immediately!

The journey was a dangerous one, full of perils, difficult to replace losses, grabbing every available unit I could get, and never having enough men. And this is what I achieved in 260BC:



BUT the bloody Romani have already built level 4 governement - what a dissapointment! All I did was for nothing! I was too slow! I cannot make Rome a nice Celtic village anymore! Now I am wondering: Could I conquer Roma even sooner?

[moonburn]

yes anphibean operation half a stack or even 1/4 stack build latters and storm the city (don´t worry with rams they always catch fire )

there´s always some windows of opurtunity and more then what one would expect the romans only leave 1 general to control and defend the city half of the times without any other unit whatsoever so depending on how close is their available field army if done correctly you can get 3 turns until the nearest roman field army can reach you

burn down the city and all structures who are useless to you (barracks notably and their goverment type must always go ) and once it´s done set up a type4 goverment with an allied general

eventually you´ll have to have a full stack of rorarii to control the city even with your client ruller at 8 prestige points but thats the priçe of keeping rome

[athanaric]

Rome will only build a Type IV government in their Italian cities if their default Type I has been destroyed previously by an invading faction (most likely you, if you're playing Gauls). So you'll face Polybian troops eventually, as long as you don't conquer too much of Italy.

[d'Arthez]

Because waiting for the Polybian reforms takes ages and I am concerned when and if it will ever happen, I became curious with another question. See, originally I wanted to "assimilate" whole Europe and make it a nice green natural area of Celts living in their villages in harmony with nature ... environmentally friendly ... ecologic ... whatever ... BUT as the Celts miss the highest level of cities, it shortens their time and forces to rush. Otherwise, some huge cities like Roma will build level 4 government building after reaching 12.000 population limit and their Roman culture cannot be overrun anymore in game. So I became obsessed with questions like:
- How can I prevent it?
- Do I have to conquer Rome?
- When can I conquer Rome the earliest?

The earliest you could take Roma is probably in (late) 271 BC, but that would require serious powergaming. In all likelihood you have to take Roma before 265 BC, to prevent the Romans from building level four governor's building.

The easiest way to make that happen would be a naval invasion, since AI tends to be very bad defending against those. As a bonus you get to avoid a couple of difficult (and thus time consuming) battles, for Mediolanum / Segesta, Bononia and Arretium, before you can get your hands on Rome.

A problem is that you start the game without ports, and having to deal with the Aedui. To commit a serious portion of your troops to a Southern campaign will come with its own challenges.
I am not sure if Tolosa has the naval harbor at the start of the game. If it does, your best bet may well be to take Tolosa, build a ship there, and put a general with some units on there. If you are lucky + somehow manage to save some money, you might be able to start a siege of Rome.