While CIV 6 is certainly not among the most demanding games out there in terms of PC requirements, there's still a significant share of low-end machines that won't be able to handle it. Trying to play multiplayer on such a machine is frustrating for everyone involved, as the game will constantly stop responding, not register any inputs, crash and then take ages to reload, or refuse to work at all.
If you want to play with someone who has these issues and have a halfway decent PC yourself, here's how you can help.

The idea of this guide is to use a Virtual Machine (VM) to run the game twice on your own PC, then stream one instance to your friend using Steam Remote Play. I will be demonstrating the process using the software VMware Workstation.
In theory, this approach should work for a lot of other games as well. For CIV, I can guarantee it, but otherwise, try your luck! Games using Easy Anticheat will NOT work.

To set expectations, please be aware that, while a weak PC is one of the main reasons for crashes in multiplayer, they can happen for a lot of other reasons as well. Doing what I'm about to show will only help if your friend's weak PC is actually the culprit. If you're having issues but aren't sure why, I recommend trying some less drastic measures first, such as decreasing the map size or the number of AI opponents or the number of mods in use. When loading into a game, it is also imperative that nobody clicks anything until everyone has finished loading, as the game is extremely sensitive during the loading process. Likewise, make sure that whoever is responsible for saving the game at the end of a session does so before anyone leaves, since players who leave will immediately be converted to an AI opponent, which can also cause problems.
Might be a placebo effect but I'm pretty sure this mod improves stability too, or at least it makes disconnects more bearable.

Extensively tested and working on this system.[www.3dmark.com]

You will need:

• At least 16 GB of RAM, preferably even 32 GB
  
• At least 50 GB of free disk space. Needs to be on an SSD, preferably a fast one too.
  
• A decent CPU. My i7-10700K seems to be more than enough already, but I also can't test it on anything else.
  
• Pretty much any graphics card at all, since the game is always going to be bottlenecked by CPU.
  
• At least 10 mbps of upload internet speed
  
• Your friend's trust (or enough money to buy the game again)

Software:

• VMware Workstation - https://www.vmware.com/content/vmware/vmware-published-sites/us/products/workstation-player.html.html
  
• EITHER the Windows 10 disk image file (ISO) - https://www.itechtics.com/?dl_id=133
  (Google for it yourself if you don't trust this link, Microsoft sadly doesn't offer an official download)
  
• OR the Windows 11 disk image file (ISO) - https://www.microsoft.com/en-us/software-download/windows11/ (the third option on this page) Warning: Windows 11 requires you to log in with a Microsoft account!

If you're feeling brave you may also try your favorite Linux distro instead of Windows, which would be even better because Linux requires less RAM. VMware Workstation is available for Linux and can also run Linux VMs, but so far my attempts to achieve playability in CIV with Linux (on Mint and Fedora) have been in vain.

Your friend will need:

• At least 10 mbps of download internet speed

You will only have to do these steps once.
To start, simply install and start VMware Player from the link above. Select "New Virtual Machine" from the dropdown menu:















Now select "Installer disk image file" and specify the path to the ISO file you downloaded:















The next steps will vary based on whether you chose the Windows 11 ISO or the Windows 10 ISO, but when you're asked to specify the disk capacity, remember that the base game needs about 20 GB, all additional DLCs need about 8 GB, and the operating system needs about 22 GB of storage, for a total of 50 GB. Resizing the disk later is possible, though you still might want to leave a bit of headroom from the start, especially if you're also going to install mods or use the VM for anything else.

On this screen, select "Customize Hardware":















In the dialog that opens, you will need to assign your VM around 8 GB of memory, preferably even 10-12 GB if you can. If you only have 16 GB in your computer, you may later need to play around with this a bit to find the optimal value. It's important to note that the amount you choose here will be unavailable to your host the whole time the VM is running, regardless of whether the VM is actually using all of it or not. Hence, if you choose too much, the game might crash on your host, and if you choose too little, the game inside the VM might crash. In any case, make sure to close absolutely everything you don't need as RAM will be tight.

Similar approach for the amount of processor cores to give your VM. Basically choose as many as you can get away with. Half of your processor's total cores is a safe bet, but more may also work.

Lastly, in the "Display" section, make sure "Accelerate 3D Graphics" is checked:


















Once everything is set, close the hardware dialog, click finish, and the VM will start automatically. If you chose Windows 10 earlier, you'll just need to wait while it is installed automatically. If you chose Windows 11, you will need to interact a bit here and there and, most notably, log in with a Microsoft account.

You should now have a functioning VM, on which you can install the Steam application like you would on a normal PC. Proceed to log in using your friend's Steam account. Alternatively, if your friend is not comfortable with giving you their account, you may create a new account on which you will need to purchase the game again. It's frequently on sale so if you get lucky, this will be a rather small expense.

But if your friend did trust you and you successfully logged in with their account, just download the game and start it. Make sure to select DX11 in the launcher, as DX12 isn't supported by the VM:














In your friend's view, they should now be able to connect to your VM instead of starting the game on their own PC:






If they can't, they may simply need to restart Steam or select your VM from the dropdown menu (the actual name will vary):











If you did have to create a new steam account because your friend wouldn't give out theirs, the procedure is instead to start the game on your VM, then accessing the Steam overlay using Shift + Tab, then activating Remote Play and giving your friend a guest link:





















And that's it! Your friend will now be able to play the game as if it were running on their own PC, but your PC will be doing all the work.

If you've made it here, consider yourself done! The following steps are not required, but can improve your experience:

1. Using the software Winaero Tweaker[winaero.com] you can disable Windows Update on your VM. This is useful because Windows will start downloading and installing them as soon as you start it otherwise, and if you rarely use the VM, there might be a lot of updates to go through each time.
   (By the way, Winaero Tweaker also has a ton of other invaluable features that have nothing to do with this guide but still deserve a mention, such as disabling all the annoyances that Microsoft has built into Windows over the years)
   
2. If your friend's stream crashes often, you may want to lower its quality, which you can do in the "Remote Play" section of Steam's settings.
   
3. After your VM has initially finished installing, you have the option to install VMware Tools. Doing this will allow you to, among other things, copy some text (like the lobby join code) on your host and then paste it in your VM, saving your friend the trouble of typing it in manually.

Thanks for reading and I hope this can help! For questions, don't hesitate to ask in the comments and/or my DMs.