Make sure you have wine installed at minimum 2.21 version (it was tested by me). Here is how to achieve this: latest wine installation
Make sure you have proprietary producer's graphic card drivers installed. For example for NVIDIA required version is minimum 410.93 (it was tested by me). Here is how to achieve this: NVIDIA GTX GeForce drivers installation
Below there is a step by step instruction how to install and run the game:
env WINEPREFIX=~/.wine32_baldurs_gate WINEARCH=win32 /opt/wine-staging/bin/winecfg
In a popup window in Applications tab select Windows 7 option. Next switch to Graphics tab and set desired game desktop resolution - 800x600. It makes the game to run in window that fits in the Ubuntu desktop.
If you want to run game in full screen mode then check the Virtual Desktop Emulation checkbox. But know that if you run the game in mentioned mode and try to switch to other application then the game will crash.
cd directory with mounted game installation dvdrom.
env WINEPREFIX=~/.wine32_baldurs_gate WINEARCH=win32 /opt/wine-staging/bin/wine setup.exe
After successful installation setup wizard will create shortcut on your Desktop that allows to run the game. If the shortcut sucks then you can run it by hand with following commands:
cd ~/.wine32_baldurs_gate/drive_c/Program\ Files/Deep\ Silver/Baldur\'s\ Gate\ Enhanced\ Edition/
env WINEPREFIX=~/.wine32_baldurs_gate WINEARCH=win32 /opt/wine-staging/bin/wine Baldur.exe