These are for the original 0AD civilisations in Alpha 23. I concluded the following from my personal experience playing 0AD. If you disagree then please comment below.
1. Athenians Strengths:
Hero characters offer great technological gains
Slingers and hoplites are decent in mass formation
Navy can be excellent
Weaknesses:
Has access to neither rams nor elephants - this makes siege very difficult. The Athenians must rely on catapults and bolt shooters for crush damage.
2. Britons Strengths:
Economic bonus
Quick development in early phase - allows early rushes that hinder enemy’s development
Decent melee troops - can easily destroy enemy siege weapons
Buildings cost less and every structure can offer a small population capacity increase
Can train unique war dogs that are effective at harassing the enemy
Weaknesses:
No archers
Buildings are not very durable
Only siege weapon is rams, and not very durable / damaging rams
Unimpressive navy
Too reliant on wood
3. Gauls
Vastly similar to Britons with 3 key differences:
1. No war dogs
2. Gauls have access to a tavern which trains naked fanatics - they are very brutal
3. No Island settlement
4. Carthaginians Strengths:
Extremely broad range of troops and siege weapons - allows for many different styles of play and strategies. Almost unstoppable in the late game.
One of the best civilisations at naval warfare - the Cothon (unique to Carthaginians) can produce and heal quinqueremes (heavy warships).
Embassy allows access to other factions’ units -great diversity.
Has the strongest wall tower (Mijdil) at 12000 health points.
Weaknesses:
Slow development in initial phases. Lack of bonuses
Swordsman can only be trained from embassy.
5. Iberians Strengths:
Talented at defence: the Iberians are given free walls surrounding the civic centre; buildings are much more durable compared to other factions. This helps with surviving early attacks.
Decent infantry - swordsman, spearman, slingers.
Weaknesses:
Only siege weapon is rams
Inadequate navy
6. Kushites Strengths:
Has access to every type of infantry unit, with their unique Nuba Clubman and champion archers.
Also decent cavalry and elephants (especially the elephant hero)
Siege towers filled with archers can be deadly
Pyramids offer 10% faster boost for workers and soldiers - can be a huge advantage if deployed appropriately
Weaknesses:
No catapults or bolt shooter.
Slow-developing economy to begin with
7. Macedonians Strengths:
Access to siege workshop - this allows siege weapons to be produced extremely quickly from every corner of your territory, which can be deadly to your opponent.
Has access to every single type of siege weapon
Weakness:
Economy develops very slowly, so may be quite vulnerable in early phases
No swordsman - they only way of defending against enemy ram attack is use your own rams
8. Mauryans Strengths:
Has access to worker elephants - if played well, the Mauryans can develop their economy extremely quickly.
Excellent range of infantry
The hero Chandragupta Maurya is an extremely durable elephant hero that can easily take down enemy structures without being killed.
Population bonus of 10%
Weakness:
No catapults or bolt shooters
Extreme reliance on food
9. Persians: Strengths:
Has access to every type of cavalry
Has access to both elephants and rams - this can be hard to defend against
Can train hero, elephant and rams from separate buildings - this saves a lot of time
Population bonus of 10%
Weaknesses:
No bolt shooter or catapults
Huge demand for resources
Very complex structure tree which is difficult to master for beginners
10. Ptolemies: Strengths:
Farming bonus
These buildings are for free: houses, farmsteads, storehouses. This can save up quite a bit of wood in the early phase, which can be invested in training soldiers instead.
Ptolemies have one of the best navy in the game; Juggernaut is the single heaviest ship in the game; lighthouse can reveal all shorelines so you can know what the enemies are up to in real time
Also decent infantry, cavalry and champions
Weaknesses:
In the village phase the only soldier available is pikemen. They walk very slowly and deal little damage.
Extreme reliance on metal. The Ptolemies can be severely hindered on a map with little mineral
Camel archers are only effective in large numbers
Many important units can only be trained from a military colony.
11. Romans Strengths:
Has access to entrenched army camp and siege walls, which can be built in neutral and enemy territory. This allows you to shower the enemy with an endless rain of rams and cavalry units
Access to catapults and rams
Strong navy
Weaknesses:
No significant weakness
12. Seleucids Strengths:
Strong navy
Elephants + catapults can be a deadly combination
Player given a choice between reformed army and traditional army
Weaknesses:
Slightly slower economic development
Relies on military colony for swordsman, archers and close quarter cavalry.
13. Spartans: Strengths:
Women can build defence towers and sentries - saves some male workforce
Allows for fast initial development
Extremely strong infantry: Skiritai Commandos and hoplites from the Stoa are unstoppable
Weakness:
Population penalty of -10%
Limited cavalry options.
Personal opinions:
Gauls and Iberians are the best civilisations for beginners, because they have a simple structure tree (easy to learn and master) and also are strong enough to survive any early attacks.
Mauryans, Persians, Spartans, Ptolemies, Macedonians are good options for more advanced players. They require some practice to get used to but if played with the appropriate strategies they can be unstoppable.
Seleucids and Romans are well-rounded civilisations with no dramatic weaknesses, so they are good for practising skills or strategies.
I also make 0AD videos on Youtube: https://www.youtube.com/channel/UCMfNFa4F-ml8KUDKn2sYspQ/playlists