Additional information:
Brennus and Boudica are both Charismatic, so they get +1
from Monuments. This could make Stonehenge good play, as happy-caps on highlands are usually low. Large numbers of cities all getting borderpops for free also denies Brennus one of his advantages, which is switching to Caste for easy borderpops.
The GW could be interesting for Boudica, as she gets less tech-trades, and when Stonehenge is already good play, you might wanna get yourself a start with Stone and get that Wonder too, not to forget the Mids, which are strong in any situation.
It might actually be the case, that this strange "SSE" kind of economy which I've never found to be strong, at least not stronger than special options and bulbing strategies could be interesting in this setup.
Of course, Mids are no need, because Highlands usually has enough rivers and at least the hills will make it very easy to run a Hammer economy, the economy that usually prooves to be the strongest in Conquest games anyhow.
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Regarding units again, don't forget the Celts Unique Building, "The Dun" , which gives free Guerrilla 1 promotion to units built in that city. I've not tested it, but I think that only counts for units that could usually recieve the promotion, so 1 move units, not Elephants, Horse-Archers or Cavs.
Combined with the highlands map, which has tons of hills, this opens up some very interesting options, like "build an army of Guerrilla units" . Those units will be almost like Commando units but a lot earlier, and with Guerrilla III, they get 50% withdrawl chance! Imagine that, you could attack a city at 0% odds and 50% of your units would survive!
Withdrawl is usually for mounted units because they come without siege, now imagine a Guerrilla-army that flies over the map, and and has no need for Siege!
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I'm sitting over an hour already at these choices. Even with this Gauntlet lasting 2 months, not many games can be played because of the length of one game.
I'm somewhat currently leaning towards trying something like Boudica + Stonehenge + Mids and then constant Police State + Vassalage + Slavery and later switch to Nationhood + Theocracy, slow-tech-setup and wipe out the map with an army of Guerrilla III. Guerrilla I comes from Duns, they're cheap anyhow because you'll have Stone, then Guerrilla II from Barracks, which are again cheaper, and Guerrilla III from Vassalage / Theocracy.
Don't forget, that those units will also all have Combat 1, so they'll be stronger than normal units anyhow. A Celtic Swordsman has a STR of 7.2 when attacking cities, that's close to a War Elephant, and now imagine that Gallic Warrior with 50% withdrawl chance, double movement on Hills and invulnarability against counter-attacks when standing on a hill due to 50% defense bonus!
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Tell me what you choose and how it's going, but don't forget to tell if you play with or without Vassal States.
That's always the hardest choice that I have to make. Generally I hate Vassal States, but I'm sure that Conquest games can be won more easily or quicker with them.
Vassaling all AIs that remain in the end is only a choice, if you vassaled all others before that also, because otherwise, you'll surpass Domination limits and the Domquest coin gets thrown, and of course, nobody wants to lose a game in which he / she maybe has invested 100h+ of playtime!
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I'll make some promotion for this Gauntlet in the Strategy and Tactics subforum, more competition always means more fun, and this one has so many opportunities, that usually anyone that can beat Deity should be interested in playing it.
Sera