Step 1: install your game through your respected platform.

Just follow the regular steps and install the game without adding any other stuff yet whatsoever.

(I personally have a legit copy of the Sims 3 on Steam. If you use another app and have any questions, I'll probably not be able to help you.)

Step 2: run the game once through the official launcher. Once you get to the main menu, you can quit again.

It is very important you run your game through the original launcher at least once after installing it. Not doing so can cause problems with programs like CC magic. You only need to do it the first time. After that, we'll be skipping the launcher entirely.

Step 3: Create a short cut of TS3W.exe on your desktop.

You'll be skipping the launcher from now on. This helps with performance and it starts up your game much faster. It is also important to do this because of DXVK.

You can find TS3W.exe in your bin folder. For me (Steam version) it's in this location: C:\Program Files (x86)\Steam\steamapps\common\The Sims 3\Game\Bin

Right click TS3W.exe, click 'show more options' and choose 'create a shortcut'. Place this shortcut on your desktop and Run Sims 3 from there from now on.

Step 4: Run the GPU Add-on Support patcher

You can find this patcher here. It is essential to run this because Sims will otherwise not recognize your graphics card unless it's over 10 years old. This patcher helps to get your GPU recognized.

The patcher will create a new Graphicsrules.sgr and new Graphicscards.sgr for you in your bin folder. After installing this, you can move the ones that have _old behind them somewhere else (or delete them).

P.S.: if you pirate your game you'll have to do this manually, there's guides online for it but since I have a legit copy I can't help you here.

Step 5: Install DXVK

Make sure you follow this guide by Nornities and do every single step. Don't skip anything!

I'd say DXVK is pretty essential nowadays, especially if you have a modern graphics card with 6GB of VRAM or higher. It'll greatly help to keep your game stable and can prevent a lot of crashes. The way Dxvk works, is that it loads textures through your VRAM instead of your RAM. Especially when you use a lot of CC or HD textures, this will make a huge difference for your RAM usage. Sims 3 can only use 4GB of RAM at once and will start crashing once you hit the 3GB mark in your task manager. With DXVK, you will use a lot less RAM and it'll take much longer for your game to reach this hard cap.

When not to install DXVK: if you have a shitty GPU (like an integrated graphics card on a laptop, or one with 4GB of VRAM or less).

Step 5: Start up the game

Use your new desktop shortcut that also has 'run as administrator' permissions now if you followed the DXVK guide properly.

Step 6: set up all your settings through the ingame options menu

The best graphics settings for you will highly depend on what computer you're using. But there are some things you should always turn off because they negatively affect performance. I will share my (relevant) settings with you (I use a custom UI so your screen style will look a little different from mine). Click on the images to enlarge them so you can read them:

Things of note about these settings:

I recommend you play in windowed mode, especially if you plan to use ReShade. Playing fullscreen is possible, but it does make Reshade presets behave differently in your game. I will include a step in this guide that you can follow to play windowed borderless. So, when you plan to do this: make sure you set the resolution to your display resolution.

Enable object hiding helps with performance. Advanced rendering is essential because otherwise your game looks like absolute shit.

Set your High Detail Lots to any value between 2 and 4. Don't go lower or higher, because you'll get rendering issues that lag out your game.

All other graphics settings can be set to your heart's desire. I'd say start with the highest settings and only go down if you notice your frames per second are bad.

Disable shop mode and lessons and fully disable memories or use this mod to severly limit them. Disable interactive loading screens as well. These are all performance eaters. Interactive loading screen also causes crashes. Memories also don't do anything for your sim, it's just a scrap book with no in-game effects.

Disable any online mode feature. This also lags out your game. Unless you really want to use these features it's best to just play fully offline.

Save your settings, close the game again.

Step 7: Install Sims 3 Settings Setter

This is the most recent magic genie that Sims 3 was blessed with. Especially combined with DXVK it is a life changer. Installing it is simple. You download the most recent version here and drop the .asi file in your bin. Also grab 'wininet.dll' from here (the 32 bit one) and drop that one in your bin too.

Start up your game and load up a save. Once you're inside your save, you press 'insert' to open up the menu for Sims 3 Settings Setter. Go to the 'patches' tab and enable what you like. These are my enabled patches and they all work really well for me, but feel free to experiment with them to find your own performance sweet spot:

Only enable uncompressed textures if you have a GPU with at least 8gb of VRAM. My game will use over 6gb of VRAM easily with this enabled, so you've been warned.

Once you have everything you desire enabled, press 'file' in the top left corner and click 'save settings'.

Step 7.5: if you're playing windowed mode: go into the Other/QoL tab and enable 'Borderless Window'. Set it to 'Full Screen'.

Save your settings and close your game again. No need to save the game you entered for this unless you want to.

Step 8: Install Nraas Errortrap, MasterController and Overwatch

These 3 mods by Nraas are pretty much essential to keep your game from breaking down in the long run. You can download the mods here. Have you never installed a mod for Sims 3 before? Here's a guide (skip the part about Sims3pack and go straight to the part where it explains how to install .package mods).

That's it! You can now play The Sims 3 and it'll be as smooth and stable as it'll ever be. From here on, you can stock your game with more mods and CC (check out my mods masterlist!), or you can install Reshade (here's a guide).

Some important things to keep in mind while playing:

Clean up your game regularly. You can easily do this by using Regul Save Cleaner.

When you install a new mod or update/change Sims 3 Settings Setter, always restart and clear your caches.

Use CC Magic for installing CC, because it merges your files and this really helps with performance. Here's a handy guide on how to use it. Don't put your script mods in here, just your CC.

If you plan to travel to vacation destinations in the EP World Adventures, Nraas Traveler is a must to prevent most of the bugs and crashes that happen in this expansion.

Always keep in mind: mods and corrupt CC can still break your game, make it laggy or unplayable. Always be mindful of the mods you add, so you can always trace any issues you're having back to the mod causing it. I highly recommend not downloading a ton of mods in one session, but adding them step by step and see what they do to your games performance.

Use 'Reset the entire town' from Nraas MasterController at least every other sim week. It'll help clear up any lag that happens because of NPC sims getting themselves stuck routing or annoying stuff like that.