Steam forces multiplayer through Steamworks. GOG’s version supports direct IP connections. You can host a server on an old laptop in your basement without Steam running in the background. This is ideal for LAN parties or playing with friends via Hamachi/ZeroTier.
Modding is the lifeblood of Terraria's longevity. Here is the status of modding for this specific GOG build: terraria 1.4.4.9 gog
On Steam, if Re-Logic releases a minor patch (like 1.4.4.10), your game updates automatically unless you go through complicated workarounds. With the GOG version, you choose when to update. If your favorite mods break on a newer version, you can stay on 1.4.4.9 indefinitely. Steam forces multiplayer through Steamworks
GOG is committed to game preservation. The 1.4.4.9 installer is archived. Ten years from now, when Steam servers might be different or your account is lost, that backup of Terraria 1.4.4.9 GOG will still run perfectly on a Windows 11 or 12 machine. This is ideal for LAN parties or playing