Baseline (Widescreen) Solution & Issues
Native widescreen support is Vert- and only detects 1280x720, 1280x768, 1280x800, and 1440x900.
Use Gothic ½ — SystemPack. This mod adds native Hor+ support for all resolutions and corrects the aspect ratio of 2D elements. FOV can be adjusted in the configuration file.
FMV cutscenes may be black or not play correctly. If this happens edit gothic.ini in the game's system folder and change scaleVideos=1 to scaleVideos=0
Characters may look fat/thin after changing the resolution. Save and load the game to correct this.
Old manual method (not recommended):
For other resolutions Edit gothic.ini in the game's system folder
Set resolution:
zVidResFullscreenX=
zVidResFullscreenY=
Set extendedMenu= to 1
Ultra/Super-Wide (21:9/32:9) Specific Solution & Issues
Same as widescreen, with this note from a user:
I have been playing Gothic 2 on ultrawide 21:9 2560 x 1080, on a new game the fov seems to be ok, but when I load a game the fov seems to change sometimes. I searched on forums and the DirectX 11 renderer seems to be causing this, I tried tweaking the fov and for horizontal I was thinking around 121.3, and for vertical I chose to leave it at 160 for now at time of typing. The fov values can be changed by opening a menu by pressing CTRL F11 and changing the values there.
More info here (you'll probably need to translate the page) - https://forum.worldofplayers.de/forum/threads/1531944-(D3D11)-21-9-2560*1080-zoomt-stark-herein-au%C3%9Fer-bei-neuem-Spiel
Eyefinity / Surround Specific Solution & Issues
Same as widescreen. Some HUD elements are at the far edges of the resolution.
4k UHD Specific Solution & Issues