For what it's worth, this is what worked for me, based on prouve's instructions on page 4, which were super helpful. I've done it a bit more step by step in case it's useful for anyone. If you're used to doing this stuff, the instructions below might be overkill.
Preparation
- Download and install Wineskin Winery (http://wineskin.urgesoftware.com/). I used Wineskin Winery 1.7.
- Download the Windows Warcraft III installer from your Battle.net account
Making a wrapper
- Open Wineskin Winery
- Add an engine (WS9Wine1.7.14 worked for me)
- Update the Wrapper Version (Wineskin-2.5.12 worked for me)
- Click "Create New Blank Wrapper". Give it a name like Warcraft3.
Setting the wrapper to download the installer
- Once the wrapper is created (it will take a moment), locate it in the Finder. Open it up with "Show Package Content" and run the Wineskin.app inside.
- Click on "Install Software", click "Choose Setup Executable" and choose the downloader .exe that you downloaded from battle.net (mine was called Downloader_Warcraft3_Reign_of_Chaos_enUS.exe)
- The installer should start. Choose where to put the Warcraft III download. I put it on the Desktop (i.e my Mac desktop). Go have lunch—it takes a while!
Setting the wrapper to install Warcraft III
- Once the installer is downloaded, open the Wineskin.app again.
- Click "Install Software" > "Choose Setup Executable", and select the Installer.exe in the newly downloaded folder (my folder was called Warcraft III 1.21b ROC Installer enUS).
- Run the Warcraft III installer. You'll need your license key. Install into C:\Program Files\Warcraft III
Setting up the wrapper to play Warcraft III
- Open Wineskin.app one last time.
- Click "Advanced". Set the Windows EXE to /Program Files/Warcraft III/war3.exe (or wherever you installed Warcraft III; you can browse for it).
- Click "Set Screen Options". Select "Override", "Fullscreen" and change your resolution to what you want. Click "Done". Close Wineskin.app.
Playing Warcraft III! (and some clean-up)
- Double-click your Wineskin wrapper. Warcraft III should run!
- Click "Battle.net" and let the updates run.
- Go back to the main menu and go to Options>Video. Set your resolution to the same resolution you selected in Wineskin.app.
- Note that you may have to get out of fullscreen mode and accept some firewall exceptions in order to play over the network.
I set up two macs running Mavericks this way and we can now play Warcraft III over the local network. I haven't tested it beyond a couple of minutes, but it seems to work well! Thanks to people who posted for getting this working.