I gained this achievement last night soon after joining gaming.stackexchange :-)
I focused on building improvements that made the biggest impact on culture (monument, temple, Mughal fort, etc.) and built as many wonders as possible (especially those that provide cultural boosts and affect the acquisition of social policies (Cristo Redentor, Hermitage).
I allied with as many Cultured city-states as possible (earning enough gold can be challenging) and picked the following policy trees (roughly in this order):
- Piety
- Freedom
- Patronage
- Order
- Freedom
As others have said, gold is a problem. With all the wonders that I'd built and the bonuses you get for playing as Ghandi (less unhappiness for larger populations) Golden Ages were more easier to start. I boosted the duration of Golden Ages by building the Chichen Itza and Taj Mahal wonders and applying the Organized Religion and Reformation (Piety) social policies. Sometimes, I also used Great Artists and Great Generals to increase their duration. The additional gold helped a lot with winning over city states, buying buildings and negotiating with other civs.
One point that may not be obvious from the achievement's requirements: you can have more than 3 cities during your play through (though you may suffer penalties in acquiring social policies) - just make sure you raze or give those cities to other players before you complete the Utopia project.
The short answer is that OliverBM's assumption seems to be correct and DLC characters are not counted towards these milestone achievements. I would've preferred more authoritative sources, but posted user experiences was the best I could do for most of them.
According to IGN, the Arcade Champion achievement does not include the DLC characters, but does include the unlockable characters:
Tag Ladder does count: You get this achievement when you beat the standard or tag ladder with each of the non-DLC 27 characters (28 on the PS3 version). You can use as many continues as you wish, and you can do this on any difficulty level.
According to this answer, Finish What You Start! does not include DLC characters, but note from reading elsewhere that it does include the unlockable characters:
And no, DLC characters dont count towards the trophy.
According to this thread on xbox360achievements.org, My Kung Fu Is Stronger does not include the DLC characters, but does include the unlockable characters:
-#112, just to be absolutely clear, even if I have the DLC characters, it only counts towards the originals?
-that is correct
According to this post, e-X-cellent!, The Grappler, and Ultimate Humiliation do not include the DLC characters**, but from reading elsewhere do include the unlockable characters:
It seems that DLC characters are not needed for trophies, I got milestone trophies (Finish What You Start !, Ultimate Humiliation, The Grappler, e-X-cellent...) without playing with Rain, Kenshi, Skarlet and Freddy.
Best Answer
The achievement is bugged. Look at this thread on GameFaqs to see the solution :)