So, after beating the game earlier today, I checked the list of secret achievements. One of them, Poetic Justice, says all the main targets need to be killed by 'indirect means.' So two questions:

1) Who are the 'main targets?' I read it was The Overseer, The Pendletons, Lady Boyle, and The Lord Regent. Is this correct?

2) What are 'indirect means?' Do you have to use the nonlethal method on each of them, or is something like a springrazor, or poisoning The Overseer's drink also indirect?

It's neutralizing all of them by indiret means, which is not killing them.
So yeah, essentially, it's the non-lethal option for every main targets. Don't remember if this includes Havelock, though...

The poisoned drink probably doesn't work, as the icon for the achievement is a branded Campbell. And, well, the title itself is also a giveaway...

Thought so. Guess this'll have to wait till my third playthrough, since this is my ultra-violent, high chaos one!

Thanks.

"You neutralized all key targets using indirect means"

You get it for choosing the non-lethal option for The High Overseer, The Pendletons, Lady Boyle, and The Lord Regent.

Yeah, I got it recently. I like letting the Overseer drink his own poison, but tried the other way to see what would happen. I prefer killing the Lord Regent, truth be told, in retaliation for his murder of the Empress. And based on what he else he did, I prefer doing it with rats. THAT is poetic justice.

I use the nonlethal option for the Pendletons, horrible as it is, because it's easier, and involves killing or harming fewer guards. And Lady Boyle's fate may not be all that horrible. At least she presumably lives a long life.

However, this time through he had retreated into his saferoom, and the only way I've found to get at him there is a hardcoe massacre. So to save the lives of the good men in the tower with him, I discredited him and left him for the headsman.

Hah, not sure about this one. "Better to die like a man (or woman) than to live forever like a slave." No?

Isn't Assassin Daud considered a main target? I mean, not "main main" but still necessary for the achievement? I'm just asking, because he's the most important character of the Flooded District.

Yes you need to dispatch everyone using non-lethal methods. I'm not sure about the last one though, don't remember it exactly.

I'm pretty sure I got the achievement before ever encountering Daud.

You get achievement as soon as you jump into water where Samuel is located on mission with Regent.