Fixes Magic Arena's broken full screen implementation on macOS

arena-macos-full-screen-fixes.sh

#!/bin/bash

# this forces Arena into full screen mode on startup, set back to 3 to reset
# note that if you go into the Arena "Graphics" preference panel, it will reset all of these
# and you will need to run these commands again
defaults write com.wizards.mtga "Screenmanager Fullscreen mode" -integer 0
defaults write com.wizards.mtga "Screenmanager Resolution Use Native" -integer 0

# you can also replace the long complicated integer bit with any other scaled 16:9
# resolution your system supports.
# to find the scaled resolutions, go to System Preferences --> Display and then
# divide the width by 16 and multiple by 9. on my personal system this ends up
# as 3456 x 1944 (versus the bizarre 1728x1117 it will very temporarily select
# when clicking the full screen option in the client
defaults write com.wizards.mtga "Screenmanager Resolution Width" -integer \
  $(system_profiler SPDisplaysDataType | grep Resolution | cut -c23-26)
defaults write com.wizards.mtga "Screenmanager Resolution Height" -integer \
  $(bc <<< "$(system_profiler SPDisplaysDataType | grep Resolution | cut -c23-26) / 16 * 9")

FYI @BlackMambaHQ, this workaround/script is working again as of yesterday's v2025.48.40 update.

Thanks for the info! That's great news. I hope that the problem will be completely solved at some point. But the solution with the script helps a lot. Unfortunately, you can't open the graphics settings, otherwise everything is set incorrectly again. And you have to restart the game.

This script needs a nice shebang line. I added #!/bin/sh to the top because it was bugging me.

There seems to be a lot of confusion in the comments. Firstly, not everyone seems to know how to run a script.

1. Download the script. Right click on the Raw button and choose Save Link As.... (The rest of the instructions assume that you download it to ~/Downloads/arena-macos-full-screen-fixes.sh, but it can be downloaded to anywhere you want, as long as you update the path accordingly.)
2. Make the script executable:

chmod +x ~/Downloads/arena-macos-full-screen-fixes.sh

3. Run the script:

~/Downloads/arena-macos-full-screen-fixes.sh

The other thing that seems to be confusing people is the launch arguments. I've tried both solutions and have found that the launch arguments solution only works if you launch Arena from the Epic Games Launcher. Unless that's how you launch the games anyway, just use the script. Another thing I found is that -force-metal 1 breaks the game. The clicks don't get through until the third attempt. I'm not sure if that's just an issue on Apple Silicon, since no ones else is complaining about this. It works fine without it though:

-screen-width 1920 -screen-height 1080 -screen-fullscreen 1

Finally, some people don't seem to understand that opening the graphics options wipes these settings and sets them back to incorrect values. So just run the script and don't open the graphics options ever again. If you do, just run the script again.