best tactics against the gauls and celtic units

[Optimus Marcus Ulpius Traianus]

As Rome i am having difficulty bring civilisation to gaul as their troops are impressive fighters and seem to best larger seemingly better armies naked fantics perticulary which break my troops who were previously winning whats the best tactics and units to use?. Ps so far i have not had any military reforms.

[Flyboy]

Defensive mode is your best friend. If you protect your flanks (usually by squaring them off) and get close enough the gauls will charge. In defensive mode your men will stay fresh, so when their line begins to get tired let your legions loose to tare them limb from limb and use cavalry to hit the rear of their weakest or wavering units, hopefully making a flood.

[Andy1984]

I used to put my cavalry in a wood nearby the main battle line, so I could charge in their back as they were fighting my infantry. I was quite surprised even the most rubbish cavalry could rout bataroas pretty easily this way. I tried to hire any kind of decent (=non-barbarian) cavalry for this purpose, especially the Hippeis Illiricoi. My first infantry line was formed by principes, because of their high defending stats. My second line - if I had one - was formed by hastati samnitici. Their pilae are better than the ones of the principes, while their shields are smaller. Initially I used a lot of accensi as well. Once I encountered more bataroas, I deployed these accensi as garrison units. They're great to have when you need to sally.
I too found defending to be the key to victory.

[Entropy Judge]

My second line - if I had one - was formed by hastati samnitici. Their pilae are better than the ones of the principes, while their shields are smaller.

Hastati Samnitici do not have Pila - they have Javelins, which are not AP. So, they tend to do better against less-armoured units like Lugoae and Gaesatae, and not so well against better-armoured ones like the Solduros and Carnute Cingetos.

My first infantry line was formed by principes, because of their high defending stats.

If, however, you're using Camillan units like the OP, you really need cavalry hammers since you're using spear-armed units.

better armies naked fantics perticulary which break my troops who were previously winning

Gaesatae are particularly dangerous to fight against for a few reasons:
They have two HP, which very few units also do;
They Frighten Infantry, which means your own units' morale will be depleted;
They are sword-armed units with high Defense Skill but low armor - this means that they are positively brutal in a melee, but if you can outflank them with Missile units (Accensi, Sotaroas, Toxotai, etc) they can be beaten fairly easily.

Uirodusios are the younger brothers of the Gaesatae, only having one HP and armed with a spear, but they also Frighten and have a Friendly Morale booster, so they're another good target for your flanking ranged units.

whats the best tactics and units to use?.

Hire spear units (such as Camillan Principes, Hastati Samnitici, and Triarii) and Pikemen (Misthophoroi Phalangitai are probably your best bet) to hold the line against heavy units like the Gaesatae while using *good* cavalry - Equites are alright, but when Leuce Epos and Illyrian Hippeis are just around the corner and so much better you should use them - to charge and repeat; do not keep cavalry in a sustained melee, and do not have them charge any unengaged units. Make sure to keep a General with the army to provide Morale boosters.

[aznflea]

the gallic units have lower morale compared to the roman units so spreading your line thinner and then flanking them works well. keep them in guard mode for best line holding results.

[Optimus Marcus Ulpius Traianus]

thanks for the advice defensive does work really well another thing i have done to crush flanks is to accompany cavalry with triarii so the better gaulic horsemen get destroyed (without the loss of many horsemen leaving them to attack from behind) leaving their flanks undefended

[Andy1984]

Another trick you can consider is not trying to fight on the open battleflields, but going straight to their cities (use spies). I've lost more than one army by Gallic generals that gave a massive +5 or +6 morale boost to their units, making them fight to death. You might want to pay attention to these morale boost of both your generals and the opponents, especially when you are playing on a higher difficulty level.

[aznflea]

strategical superiority can directly impact your tactical situation so be sure to keep an eye out for river crossings, bridges and mountains

[V.T. Marvin]

Another useful tactics agains Gauls, Luso and other situations where nearly every enemy unit has some javelins to throw is to place your skirmishers (Leves or Velites) in loose order, guard mode and fire-at-will on in front of your hastati (with guard mode and fire-at-will on).

This way the enemy spends his javelins on your cheap skirmishers without causing too high casualties (thanks to the loose order) while being in turn peppered by the pila of your hastati when tiring himself in fighting your skirmish line. When you see your skirmishers wawering, order them back to reform. The enemy now engages your hastati, tiring himself even more and being now bombarded by the pila of your principes - so that when the appropriate time comes for your principes to charge, he will be unable to withstand the arrival of new fresh troops and usually routs.

Of course, this coud be easily combined with other sound tactics suggested above.

[Pode]

Defensive posture in the triplex acies. Learn it, love it, live by it. Naked fanatics are the only celtic units I've seen not route to a charge by fresh principes while engaged vs hastati after having been harrassed by slingers, velites, and the hastati pila as they approached. I've never had to move my triari except in response to cavalry flankers or to finish off the nudists after the rest of their army scatters. Pick up a unit of archers with flaming arrows for extra dismay as they close in.

[frontier-auxilia]

Defensive stance, keep reserve to counter flankers or filled a hole, superior missle troops so they can come to a ground of your choosing and eat Pilas as well. Then after prolong engagment, have a cavalry unit to rip them a new s (elequonely put, attack the rear of their wavering units) preferably have them sit in a bush eating pop corn before the time is right to unleash them as the enemy will most likely comit the rest of his troops on your line instead of countering your flankers. As previous posters said do not let them stay in hand to hand for its the shock you needed from them to break the enemy lines, getting them tie up will result in butchered tax collectors and horses.