If you are looking for the full, stable experience with modern support, these are the primary legal sources:

: If you own the base game, major community mods like Horn of the Abyss (HotA) provide massive amounts of new content, including new factions and mechanics, entirely for free.

: You can play Heroes of Might and Magic III directly in your browser without downloading via the DOS.Zone project .

: The current owner of the franchise occasionally offers older titles for free during special anniversary events or sales.

: Offers the Heroes III - HD Edition which features updated graphics but lacks the original expansions.