This guide will show you how to run Apex Legends letterboxed down to a 21:9 aspect ratio on a standard 16:9 (1080p/1440p/4K) monitor. Why would you want to do that? Well there are two big reasons:
First, using an ultrawide resolution allows you to increase your field of view without jacking the FOV slider up and distorting the image. In a battle royale game seeing the enemy first grants a huge tactical advantage, and a wider FOV makes it easier to spot enemies first and makes it harder for flanking enemies to sneak up on you.
Second, since your card is rendering 25% less pixels performance should see a considerable boost in most cases. Standing on the first hill in the tutorial stage my 1070's framerate at 1440p (2560x1440) is 62fps. But letterboxing down to 2560x1080 that shoots up to 80fps. That's around a 20-25% improvement. If you're struggling for frames on a weaker PC or on a high refresh rate monitor this is a great way to boost performance without lowering the resolution in a way that blurs the image.
You are, of course, giving up about 25% of your screen space to black bars for this. That seems like a big sacrifice, but if you're on a 27" or larger screen in my opinion it's worth it for the gameplay and performance advantage it provides. It also just feels more immersive and more natural. And it's cheaper than buying an ultrawide monitor!
You can actually get most games to run ultrawide letterbox, but it varies by title and can be a little tricky. So I'm going to walk you through the steps that are specific to Apex Legends. I'm using an Nvidia GTX 1070 on a 32" 1440p/60hz monitor.
Create a Custom 21:9 Resolution
First you need to add a custom resolution to use. This can be done from your graphics card's control panel. I have an Nvidia card so this tutorial will focus on that. You should be able to do the same things on an AMD card, though, but you might need to Google the specifics.
1) Right click on your desktop and select Nvidia Control Panel from the pop-up menu.
2) When the panel opens, on the left open the "Display" menu and click on "Change Resolution".
3) You'll see a list of resolutions. Click on the "Customize…" button below them.
4) Another menu will pop up. If it's not already checked, click the checkbox for "Enable resolutions not exposed by the display".
5) Click "Create Custom Resolution".
6) Now we just need to change "Horizontal pixels" and "Vertical lines", which should show your current desktop resolution to start with. (don't touch anything else!)
7) Now we'll adjust the Vertical line count. Based on your monitor's native resolution, enter the new resolutions below (you probably only have to adjust the right vertical one). In theory you can also pick a higher resolution and downsample for a nicer image, but for compatibility I'd stick with these numbers at first:
1080p monitor: 1920x810
1440p monitor: 2560x1080
2160p monitor: 3840x1607
8) Now click "Test". Your desktop resolution should change, leaving black bars on the top/bottom. As long as the popup says "test successful" click "Save" to save this resolution option to your PC. Your resolution will return to normal, but you'll see your new resolution in the list in front of you. Click Okay.
9) Now on the far left of the Control Panel under Display click "Adjust desktop size and position".
10) Under "Scaling" select "Aspect Ratio" for the scaling mode and from the "Perform scaling on" menu pick "GPU". Then make sure "Override the scaling mode set by games and programs" is checked. This is to prevent the game from stretching the image vertically on us.
11) Click Apply to apply these settings then close the control panel.
Okay, that's the hard part. Those custom 21:9 resolutions will now show up in Apex Legends (and most other games).
Configure Apex Legends
1) Now open Apex Legends. On the lower right of the screen you'll see "Game Menu". Click on the gear icon on the right.
2) Now at the top of the screen click on "Display" to open the display menu.
3) For Display Mode you will want Full Screen.
4) Under Aspect Ratio pick 21:9
5) Now our 21:9 resolution should show up right below! Click "Apply" at the bottom of the screen and the game should switch to 21:9 letterboxed mode with black bars on the top/bottom of the screen.
6) If the scaling isn't working right (the image is stretched) another option is to change the desktop resolution to the 21:9 resolution, then in-game select "borderless windowed". You have to do this in some other games.
And that's that! Initially ultrawide can feel odd and you find yourself missing the screen space. But you'll adapt quickly to that and soon find the extra wide view liberating.
Hope some of you find this useful! If you have any questions feel free to leave them below. Note that this guide WILL work in PUBG, but will NOT work in Fortnite. Fortnite is tricky to get working, there are a couple more hoops to jump through. I may make a separate guide for it eventually, but for now I'm putting an abbreviated guide down in the comments.