There are two convenient ways to install HotA on macOS.
GameHub lets you install HotA both from the Steam game store and via the standard installer. It works only on Macs with Apple Silicon (M-series) processors.
Heroic Games Launcher lets you install HotA both from the GOG game store and via the standard installer. It works on Macs with both Intel and Apple Silicon (M-series) processors.
Choose whichever method is more convenient for you.
GameHub
Download and install GameHub from https://www.gamemac.com
Launch GameHub → sign in with your Google account
Installing the Steam version
Sign in with your Steam account
Install Heroes of Might and Magic III: Horn of the Abyss from your Steam library
Launch the game
Installing the standard version
Select Library → Add Game → Local Game → select the Heroes of Might and Magic III: Complete installer (.exe)
Select the added installer → click Play → complete the installation
Click the ⋮ button → select Game Settings → in the Game path field, click the ⇆ button → select the HotA installer (.exe) → click Back
Click Play → install HotA into the Heroes of Might and Magic III: Complete folder
Click the ⋮ button → select Game Settings → in the Game path field, click the ⇆ button → in the HotA folder, rename h3hota HD.exe to h3hota_HD.exe → select h3hota_HD.exe → click Back
Launch the game
Heroic Games Launcher
Download and install Heroic Games Launcher from https://heroicgameslauncher.com
Launch Heroic Games Launcher → go to Wine Manager → Wine-Crossover and install Wine-Crossover-latest
Installing the GOG version
Click Log in → GOG LOGIN → log in to your GOG account
Click Library
Find and select Heroes of Might and Magic III: Horn of the Abyss
Click INSTALL
Click Show Wine Settings → select Wine Crossover in the Wine Version section → click INSTALL
Launch the game
Installing the standard version
Click Library → ADD GAME
Click Show Wine Settings → select Wine Crossover in the Wine Version section
Click RUN INSTALLER FIRST
Select the Heroes of Might and Magic III: Complete setup file (.exe) → complete the installation
Click RUN INSTALLER FIRST again
Select the HotA setup file (.exe) → install it into the Heroes of Might and Magic III: Complete folder
Click Select Executable → select h3hota HD.exe in the HotA folder → click FINISH
Launch the game
Additional Notes
Use the ADD GAME button to create shortcuts for editors (e.g., the map editor).
To do this, select the editor’s .exe file in the Select Executable field.