In standard game mode, it says on the card: "At the end of the round, if Dol Guldur's city strength is 0 and there are no Lieutenant enemies in play, Dol Guldur is captured and the players win the game."

I'd been thinking I'd have to destroy more than 1 Lieutenant due to the "When Revealed" on each stage 3 saying the relevant Lieutenant goes into staging, unless it's in the victory display. However, in looking again at the card above, it seems like a kind of "passive game state" I'm to always check, where as soon as it's true (meaning I need to destroy 1 Lieutenant, and that's only possible when the city strength is 0) then at the end of that round -- before I'd do any Forced effects -- I instantly win.

Is that right? Or am I missing something where the Forced effects are to first take place and rotate in another Lieutenant after I've destroyed my first one?

You can't destroy any lieutenant until Dol Guldur is at 0 strenght: all lieutenant are indestructible.

So, no matter how many players there is you have to, on the end of the turn have on the same time all lieutenant in play with as many damage as life point and Dol Guldur at 0 strenght.

I hope it is clear enough

Yes, as I said, when the city strength is 0, I can destroy the 1 Lieutenant in play.

But in stand game mode, there can only be 1 Lieutenant in play at a time -- the other 3 are all "out of play".

Therefore, at the end of the round, it appears I have met the win condition, because there are now no Lieutenants in play.

So in standard game mode, all you need to do is destroy 1 Lieutenant and you win?

Yes.

Sounds good. So then how is it ever possible a Lieutenant will exist in the victory display, as per the "When Revealed" wording on the stage 3 cards?

Because the passive effect of winning the game (city strength zero, lieutenant dead) triggers before the forced effect (on Dol Guldur and the game mode card) of advancing to a new quest stage, and therefore the when revealed effect of adding a different lieutenant.

I wasn't clear. I see how a lieutenant ends up in the vd (city strength 0 and I destroyed him). What I don't understand is how I can ever reveal a new stage 3 card and the "When Revealed" condition says the lieutenant might be in the vd. Because by that time, the game is over, so it'll never happen. (But maybe that's really only relevant in Epic mode, and is impossible in Standard?)

It is only relevant in Epic mode, since city strenght can be 0, 1 lieutenant put on victory display but the others have not enough damage. So he come back.

Unless the quest stage corresponding to the one you killed is not chosen to be active the next round.

OK, so in standard game mode, the game is over (at the end of the round) after I destroy 1 lieutenant. Thanks.