City of the Damned (Act 4) Farming Guide - Diablo 2
How to Reach: City of the Damned (WP)
Zone Level: Nightmare: 57 -- Hell: 84
Golden Chest: No
Boss/Champ Packs: 3 - 7
Hell Immunities: Lightning (Abyss Knight, Damned, Dark Familiar, Strangler), Fire (Pit Lord), Cold (Stygian Hag, Stygian Dog), Poison (Corpse Spitter)
City of the Damned is one of the few areas in Act 4 and also the best 'open' zone that you can farm in the game since it has the highest Area Level of all open/field zones. What I mean by 'open' is that the area is basically not a dungeon. There are two types of zones in Diablo 2, dungeons and "fields", this zone is basically one of the "fields" in the game. Any classes and builds that benefit from fields (like Bowzons) are who this location will be best for.
Since City of the Damned is a level 84 zone in Hell difficulty it means that it can drop all but the highest Treasure Class in the game. Technically the Unique/Boss packs can drop the highest Treasure Class, since they will be 87 but it's much more rare than level 85 zones. For more information about how all this works check out my Magic Find Guide, it goes into more detail and explains it all better.
Your takeaway (if you don't understand Treasure Class and all of that very well right now) is that the difference between a level 84 and 85 zone is extremely small. Unless you are specifically searching for the absolute best loot in the game there won't be much of a difference between level 84 and 85 zones.
Note: City of the Damned, Outer Steppes and Plains of Despair are the 3 highest area level outside/field zones in the game. All three of these zones are located in Act IV next to each other which makes them easy to all hit in one farming rotations. River of Flame is pretty open too and worth checking out; bonus points for that zone since it is a level 85 zone!
City of the Damned has more Lightning Immune mobs on Hell than any of the other overworld zones throughout Act IV. Abyss Knights, Damned, Dark Familiar and Strangler are all of the Lighting Immune; there are also 2 Cold Immune, 1 Fire and 1 Poison. Since there are so few of those immunities it wouldn't be too difficult to skip them when you run into them if you don't have the means of defeating them.
Lighting users though, there are too many for you to skip. You will end up dragging packs of Immune mobs into packs of mobs you enemies you can kill and it'll end up being a mess. Just be thankful that City of the Damned doesn't have any of the insanely overpowered Chain Lightning enemies like Plains of Despair does.
All in all though, City of the Damned is a pretty easy location to farm. It doesn't have any insanely overpowered enemies that you need to keep an eye out for, just annoying immunities.