Any specific Barb behaviours You have observed

[Leyrann]

To be honest I am a little tired of reading such sentences, just because they are hardly realistic. Even if you do not move your starting warrior, you won't catch that scout who turns around the second he spots your capital. And I cannot clear a camp that is still in the fog of war. And because the human player is usually far behind in science in the early game, the barbarian units are more advanced than your own, and you need much time and many many units to clear a camp.
If you do not experience those things in your own games, you are one incredibly lucky person, congratulations. I wish you all the best and lots of fun!

It is indeed quite common for the player to be unable to clear a camp that spawns at game start before it scouts the player. However, that just means that if a scout finds your capital on turn 4, you switch to a slinger or warrior as soon as you finish your first scout. Assuming that's what you started with, of course. If you started monument or builder, you chose greed and should accept the risks associated with that.

You can find the camp simply by exploring the direction the barbarians came from.

In my experience (and this is on deity) camps do not start spawning more advanced units until at least turn 50; they can spawn horsemen earlier, yes, but those actually only have 20 combat strength, so if you simply put in the combat strength versus barbarians card your warriors can easily take care of them. The barbarian horse archers even more so, they don't deal all that much damage, but fall quite quickly if you attack them.

I am not a lucky person, I simply adapt my playstyle if needed so that I can deal with the barbarians. That's part of the game, and the design philosophy for Civ VI; you can't just close your eyes and cruise straight ahead, you have to adapt to the map and consider what the optimal strategy is with the hand you're given. And even then, I mean, bad games happen. Here's the screenshot I mentioned in the previous post:

View attachment 625538

Horsemen, horse archers, even a catapult - and I had already killed another catapult that came from the other direction, part of the army that attacked my capital and got it to zero health a few turns before this. (note how it's turn 63 and apart from the catapult it's all starting units)

How did I deal with it? By gearing my entire empire to fighting them, for the moment. I used the combat strength bonus against barbarians card, I selected oligarchy, and I even slotted in the Twilight Valor dark age policy, my first time ever (!) using a dark age policy. As you can see, I was also building quite a few military units (I lost several in my battles with the barbarians), and my warriors are at practically zero health because I was playing to the absolute limits.

But you know what? I got a great story to tell for it, and in the game itself, I recovered magnificently. Here's what the empire looks like only 107 turns after the above screenshot, now in the Industrial Era. Just look at the yields. And notice how I've caught up to most Deity AIs in terms of culture and science.

(oh and as it happens, I'm still dealing with barbs in the north, lmao)

 

[Minou]

Not sure if this was already posted, but Barbarians can't kill your capital. They can take it to 0HP but can't capture or raze it. Sometimes if babes raid early I just ignore them completely and settler my second city in the opposite direction. The melee units will batter themselves against the city and eventually you can just pop 1-2 units and kill the rest off.

Of course this does not keep them from pillaging districts, but by the time you have your first districts complete you should have enough units to stop most barbs.

Barbarian Clans mode generally makes barbs less dangerous - they seem slower to raid and if you do have a camp spawn near your capital, you only need 95g to buy a Warrior or Horseman from them in most cases, which is often enough to stop them in their tracks - if you fortify the hired unit on a hill/forest and use the Discipline card they will usually suicide into it.

 

[SirNovelty]

Not sure if you're looking for this kind of thing, but I booted up a Barbarian Clans game just now, and noted that the window to buy and process of offering unique units is pretty strange. The Grey Rat clan formed on turn 15, I hire a Warrior from them on turn 18, but suddenly on turn 25 they claim the Okihtcitaw as their unique unit. Unfortunately they started hiring archers the very turn my cooldown expired, but I thought it was weird that UUs aren't claimed immediately when the tech is unlocked, or at any specific time after clan formation if I'm reading the log correctly.

 

[Oberinspektor Derrick]

Not sure if you're looking for this kind of thing, but I booted up a Barbarian Clans game just now, and noted that the window to buy and process of offering unique units is pretty strange. The Grey Rat clan formed on turn 15, I hire a Warrior from them on turn 18, but suddenly on turn 25 they claim the Okihtcitaw as their unique unit. Unfortunately they started hiring archers the very turn my cooldown expired, but I thought it was weird that UUs aren't claimed immediately when the tech is unlocked, or at any specific time after clan formation if I'm reading the log correctly.

I have no idea what triggers the different units myself, but it's probably a good thing.
Standard units from camps are severely underpriced already, and offering unique units (for roughly the same, heavily discounted price) just breaks the early unit economy.
Buying Legions or Immortals for an early rush for example, you kinda just gotta do it because of the value you get.
Or buying the infamous man at arms on turn 20-30, just lol.

 

[Oberinspektor Derrick]

Not sure if this was already posted, but Barbarians can't kill your capital. They can take it to 0HP but can't capture or raze it.

Was gonna write just that, but this excellent summary beat me to it.
This is the way to handle early barb invasions.
As long as you didnt open builder first or rushed a district, you can just ignore those barbs completely, as they will suicide onto your capital while you keep doing your thing.
Heck, even builder first is no disaster as long as you keep 1 builder charge for repairs the second you spot the invasion.
It can get somewhat annoying as it can delay a settler, but usually the barbs killed themselves within 5-6 turns anyway, which is manageable.

Now if they spot your settled city however... you might actually be in trouble.

 

[Minou]

I've never been able to figure out (1) what triggers a Barbarian Clan to start offering a new unit, (2) the odds of getting a tech boost from clearing an outpost, and (3) the formula for progress towards becoming a City State.

I think T20 is the earliest they will offer a Unique Unit on Standard Speed, but this just seems to be when they have a chance of swapping rather than all camps shifting on that turn. It can be pretty damn amazing when you can buy an Eagle Scout for 155g! I'm also not sure about when modern units get unlocked, but I think it is triggered by player progress because my last game I had a clan selling Battleships around T90 when most AIs were still running around with Swords or Man at Arms. It's really hilarious to imagine - you walk into a clearing and there are some dudes hanging around a fire by some grass huts. They turn to you "Hey, buddy, wanna buy a Battleship?" and its parked over to the side under a tree.

The tech boosts I always thought were limited to Ancient Era, but I once got Engineering. I assume the odds are better if the player is behind in techs and possibly the boosts are only available if multiple AIs have them.

Progress towards city states is straightforward for the things you can pay for such as "5 turns" for buying a unit. But the passive rate clearly speeds up a lot based on player progress, probably based on techs/civics completed. Sometimes a clan will also go to "City State conversion disabled" and I have no clue as to why this happens to a given clan and not another.

 

[steveg700]

To be honest I am a little tired of reading such sentences, just because they are hardly realistic. Even if you do not move your starting warrior, you won't catch that scout who turns around the second he spots your capital. And I cannot clear a camp that is still in the fog of war. And because the human player is usually far behind in science in the early game, the barbarian units are more advanced than your own, and you need much time and many many units to clear a camp.
If you do not experience those things in your own games, you are one incredibly lucky person, congratulations. I wish you all the best and lots of fun!

Essentially correct statements. It'll take two attacks at least to kill the scout, at least. Gotta be in an position between it and the camp in order to intercept.

I always opined that the obligatory geyser of barbs shooting out one per turn--even two at higher levels-- needed reining in at the ancient era. Certainly before the +5 card is likely to be available. And the bit where they spawn anything that has been researched by anyone was not in keeping with barbarism or terribly necessary. We got geysering mostly because there are too few hexes to allow most camps the ability to fester over time. If they spawned in a sane and reasonable fashion--say, comparable to a city's production rate--they'd get wiped nonchalantly more often than not. The Old World seems to have sussed it out: tribes start with an initial amount of troops that don't stray from the camp to far. They send out raids after a build up period.

Once the geyser starts, generally best not to charge in with one warrior to clear the camp. The best tactic at game's start is simply to find a defensible bottleneck and let them impale themselves. Barb warriors die easily to this. Slingers force a response that breaks fortification, but at least they're easily smashed in one hit. Archers make for a problem and simply require that players have forces on-hand. Horsemen are a little more dicey, though they'll still die to fortification. Swordsmen can show in the ancient era, men-at-arms in classical. That can get aggravating if they got what you don't yet. Hope for some CS to pitch in.

The quadrireme....Now that's the big inducer, as it combines two wonky systems we never needed. First, the aforementioned barb getting cutting edge tech. Second, naval vs land not playing by fair-and-square Strength-vs-Strength rules. The quad can appear in the ancient era, obliterate warriors while archers plink away with little effect.