So one thing that's come up a lot recently is barbarians. IMO, barbarians are integral to the gamestate of FFH/EitB, and the game is built around them to such a degree that playing a game which does not include them is tantamount to playing a variant on its own.
EitB 38 SPOILERS:
Not only this, but I believe that the inclusion of barbarians is something that is beneficial to the balance of the game, especially in a FFA as opposed to a duel.
I would firstly point out that a distinction needs to be made between barbs and lairs. Lairs are a contentious issue on this forum, and not one that I think has a right/wrong side, so to speak - I hold a position, as do others, but I don't think the opposing position is wrong. For this reason IMO lairs need changes to be integrated/developed, (which is currently under review) whilst barbs do not.
Let's look, then, at what barbs do.
Barbarians begin to appear ~t5, as animals. Animals are basically just normal barbarians, except they are passive, never entering your borders or besieging your cities, but attacking anyone wandering the wilds. They have a more variable strength range than the normal barbs, going from slightly weaker (wolves) to significantly stronger (hill giants), but never scaling by game speed - they are a significant threat to explorers early on, but become less and less of a one as time goes on (there are certain rituals that alter this, but they never come into play so, IMO, they're not relevant here).
A little while later (dependant on difficulty, but I believe once there are 1.5x as many cities on a landmass as there are players) "normal" barbarians start to come into play, in the form of orc warriors, but slowly increasing in strength as the game techs on. These "normal" units are the ones that invade your borders, and the ones the Clan, Charadon and Furia are at peace with. Eventually, they will found cities, which produce kill-teams to strike at players.
Now let's look at what mechanics involve barbarians explicitly:
- Subdue Animal(/beast), a promotion pretty much solely used versus barbarian animals. Losing this is a formidable nerf for the hunting/recon line, who can usually take advantage of this to capture a number of animals for cheap culture, happy and (in the case of Spiders/Scorpions) free silk and the valuable PB promotion. Even more importantly is the use of the military applications of these animals - especially Spiders and Griffons, whose Animal Invisibility and flying respectively, as well as high combat strength, makes them useful far into the late game of FFH.
An example of the former can be seen in EitB31, where the Luchuirp team used an early hunting to capture a large number of bears, which they used as cheap culture (+happy boost) for all cities. This is particularly relevant because this was a team which had no normal incentive to go this route.
- Barbarian teams, explicitly the Clan, Infernal, Furia the Mad, Averax the Cambion and Charadon, who all get a pretty clear nerf out of this.
- The Clan are shafted in particular, because they also lose their Goblin -> Wolf Rider mechanic.
- The AC is hit quite hard. I don't recall whether or not the Horsemen still appear, but the loss of the Demonic Champions and the later effects definitely lose out. This is another nerf for the BAR teams, an even larger one for the Sheiam in general, as well as a general one for those who have a better time surviving the apocalypse (Basium, Luchuirp, Elohim and so on).
That's just the obvious stuff, however. Losing barbarians also has a ton of follow-on effects which substantially alter the balance of the game.
- Some traits are nerfed, and some are boosted. AGG, CHA and, to a lessor extent, RAI are substantially nerfed as they lose a lot of their utility in a) fighting back the early pressure of barbs and b) being able to make use of the extra promotions generated from this. Others, especially the economic traits of FIN, CRE, EXP & IND recieve a boost by having less "distractions" - but above all the passive xp traits of SPI/ARC/ORG.
- Loss of Subdue Animal is another blow to CHA/AGG, which each find it substantially easier to get.
- Early military is much, much less important. Where normally a warrior is an early build, and several are generally needed before even the first settler, here you can manage without a single warrior. That's just the very early impacts, but it continues to have a profound effect for scores and scores of turns, with just that much less militarization, to the point where the "farmers gambit" becomes that much more important.
This is all a substantial change in the very focus of the game - as Bob once put it to me, "In BTS you build your army to defend your cities, in FFH you build your cities to help you make your army." (Horribly mangled, I'm sure.)
- As a result of the above, early game military techs/resources (bronze) are that much less valuable.
- Scouting is much more survivable/easy. Where normally the wilds of FFH are incredibly inhospitable, with the brief window in the first dozen turns often being the most scouting one is able to do for a long time, in a no-barbs game there is little-to-no opposition to ones scouting, something which a) changes the atmosphere considerably and b) means revealing territory is that much easier.
- The sea is also that much more hospitable.
- Experience is significantly harder to get.
This nerfs the Sidar massively, as they can normally can use barbarians to get wanes in the mid-game - without barbs they are a win-more mechanic, which would rarely come to play before the game is decided.
It also makes other units which require a xp level to get much harder - vamparism, mages, High Priests, Aeron's Chosen, and so on.
Conversely, the Luchuirp and their experience-less golems are greatly boosted by having their major disadvantage largely detracted from.
- Recon is significantly nerfed (as mentioned earlier) because of the absence of animals. This hits Sidar, Svartalfar, in particular, and Ljolsofar to a lessor extent.
- Teams with bonii to exploration - Dwarves, Elves, Sidar - are nerfed.
- Basium/Brigit have a harder time restoring immortality.
That's all that leaps to mind, but the list goes on and on. The TL;DR of it all is that No Barbarians is very much not the
default setting to go on - the changes resultant are major and have massive effects on the atmosphere and balance of the game, enough so that to have that setting on is effectively imposing a variant on the game, on the same scale as Last Days or Barbarian World, and only a step below starting an era in or playing with No Settlers. It's not a bad setting, but it is a transformative one.