The highly anticipated mod Fallout: London is out now on PC, but playing it isn't as simple as other Fallout 4 mods. Below, we detail the steps you'll need to follow to install and play Fallout: London, whether you're using a copy of Fallout 4 on Steam or GOG.

The giant-sized mod's launch comes after years in development and some struggles stemming from the release of the Next-Gen update for Fallout 4. It's an entirely new experience from anything previously released in Fallout 4. There's a completely fresh and large-scale map, a fully written story, voiced characters, and plenty of factions to join.

Requirements to play Fallout: London

First and foremost, there are a few different requirements you need to meet before you're able to download Fallout: London. Those requirements are listed below:

• You must own Fallout 4 on either Steam or GOG
• You also need to own every Fallout 4 DLC and content pack, including Automatron, Far Harbor, Nuka World, Wasteland Workshop, Contraptions Workshop, and Vault-Tec Workshop
• If you're on Steam, you need to downgrade Fallout 4 to version 1.10.163.0 (to avoid the Next-Gen Update)

If you meet all the necessary requirements for Fallout: London, you can download the mod from GOG by using the site's Galaxy launcher. This requires you to make an account with GOG, but after that, you're able to download the mod and apply it to your Steam or GOG copy of Fallout 4. All of this is explained in more depth on Fallout: London's store page on GOG.

Playing Fallout: London on GOG

For those of you who decide to play Fallout: London on GOG, you certainly made the easier choice. The developers of the mod have a partnership with GOG and thus it's much simpler to download. This is primarily because you don't have to downgrade Fallout 4's version if you purchase the Game of the Year Edition from GOG. If you buy this version, all you have to do is install the game and then download Fallout: London from GOG. Right now, the Game of the Year Edition is only $16 on GOG, which is a 60% discount from its normal price.

To download Fallout: London, you also need to download the GOG Galaxy launcher, as that's where the download of Fallout: London will end up. It's also where you can access your copy of Fallout 4: Game of the Year Edition. Once everything has been installed, simply launch Fallout: London and you'll be able to play without any further hassle.

Playing Fallout: London on Steam

While GOG is the easier platform to play Fallout: London on, many players already have their copy of Fallout 4 purchased on Steam. For anyone who doesn't wish to purchase the game again, you can still play the mod on Steam, but there are several additional steps involved. First off, you need to ensure you either have the Game of the Year Edition purchased or that you have every possible DLC and content pack downloaded. Second, you still need to download the GOG Galaxy launcher, as that's the only application that Fallout: London can be played from. Download the mod from the launcher once you've logged in.

In addition to all of that, you also need to downgrade your copy of Fallout 4 on Steam. The developers of Fallout: London ran into massive issues after Bethesda released the Next-Gen Update for Fallout 4 over the summer, so you have to be on an older version of the game for the mod to run. Unfortunately, the downgrade process takes a ton of time and isn't the simplest task to accomplish. We'll explain in more detail below.

How to downgrade Fallout 4 on Steam

The easiest way to downgrade your copy of Fallout 4 to version 1.10.163.0 is by using the "Fallout London Downgrade and Addons" mod from Nexus Mods. This mod was developed by the same people behind Fallout: London and successfully downgrades your copy to the required version. It also installs some key files required for the mod to work properly.

The steps to install the mod are all laid out on the Nexus Mods page. However, we'll also give you a brief overview of the steps below:

1. Download the mod and then run the Fallout London Downgrade application (the .exe file)
2. Find and enter the install path for your Steam copy of Fallout 4 (located in Program Files (x86)\Steam\steamapps\common\Fallout 4). The folder you enter needs to be where Fallout 4 is currently installed
3. After selecting the right path, log into your Steam account and press "Install" when prompted
4. The downgrade process can take hours to complete, so keep your PC on and wait for it to complete
5. Once the downgrade has been completed, log into the Galaxy launcher and access Fallout: London (assuming you've already downloaded the mod)
6. The mod acts like a standalone game, so don't try and launch Fallout 4

With all of that done, you can now play Fallout: London from Steam or GOG. The most difficult part of the process is waiting for the downgrade to complete if you're trying to play on Steam, but it's well worth the wait.

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