Baseline (Widescreen) Solution & Issues
Widescreen resolutions are natively supported in the setup tool (Config\The Bard's Setup.exe); you can also set the resolution with ScreenHeight and ScreenWidth in the registry (choose Decimal mode): HKEY_CURRENT_USER\Software\inXile Entertainment\The Bard's Tale
Menus, gameplay and rendered cutscenes are Hor+ while FMV cutscenes and loading screens are pillarboxed 4:3. Everything has the correct aspect ratio.
The classic games available in-game do not maintain the correct aspect ratio, instead stretching to fill the screen from an internal resolution of 320x200; run in a 4:3 resolution when playing the classic games to have the correct aspect ratio.
Ultra/Super-Wide (21:9/32:9) Specific Solution & Issues
Eyefinity / Surround Specific Solution & Issues
The world tiles to the right end before the edge of the resolution. The severity of this issue will vary based on the aspect ratio and zoom level.
4k UHD Specific Solution & Issues