This page explains how to install Diablo II and play it under Archlinux. This works as of latest patch 1.13c.
Install the wine package.
# pacman -S wine
Download Diablo II and Diablo II Lord of Destruction installation files from battle.net. I downloaded them on Windows and them moved via USB stick. You can also run the downloaders directly from Arch. They will produce 2 folders: D2-1.12A-enUS and D2LOD-12.12A-enUS (locale may be different for you).
After that, go to first folder and run
$ wine Installer.exe
Enter your product key which can be found In your battle.net account and install. After it is finished, go to the second folder and run the same command. Once both are installed, download patch 1.13c from the Internet as updater will not work. The file name is LODPatch_113c.exe. After that, run:
$ wine LODPatch_113c.exe
Now you need to configure the graphics. Go to ~/.wine/drive_c/Program Files/Diablo II (or where ever you installed) and run:
$ wine D2VidTst.exe
Click on Run Test. Once it's finished, pick whichever you want. Generally I prefer 2D even on Windows as very few modern cards support Glider. You can try 3D though and see if it lags or not.
Then, add Game.exe and make sure it uses ALSA under the sound tab and that it is emulated as Windows XP. I didn't have to change anything as those were default for me.
If you use a desktop, you can create a shortcut. Otherwise just run:
$ wine ~/.wine/drive_c/Program Files/Diablo II/Game.exe