While LAN works well, Battle.net on 1.31 is empty. You’ll need third-party tools like Eurobattle.net or W3Champions to play online, and even then, connection drops are more frequent than on 1.26.
The only safe source for a pre-patched 1.31 client is the via third-party archival tools (like CASC Explorer) or trusted community repositories (Hive Workshop, Epic War). We will point you to the least risky methods. Warcraft 3 Frozen Throne 1.31 Download
: Added beta support for Lua, making it a "sweet spot" for many custom map creators. While LAN works well, Battle