WC3 CLASSIC POST-REFORGED GUIDE

>I have classic WC3 installed, what should I do to not lose it to Reforged?
Don't let it update, never launch it with the Launcher, only Warcraft3.exe.
>I don't have classic WC3 installed, can I download the old client from Battle.net?
No. That client has been replaced with a 30GB version of Reforged with new graphics turned off.
>Can I just install the game from my CDs?
Yes, but the highest version you can get to offline is 1.27b. ANY non-Reforged client will immediately try to install Reforged if connected to Battle.net.
>Can I play on official Battle.net with my classic client?
No.
>I just want to play WC3 campaign for the first time. What version do I download?
Without widescreen? 1.26b
With widescreen? 1.30.1
>What are the differences in versions?
1.26b is the most bug-free single-player. This version does not have official widescreen support. Unofficial widescreen mods exist but stretch the UI: https://www.hiveworkshop.com/threads/renderedge-graphic-modification-for-warcraft-iii.288375/
1.27b is the latest offline version (only requires the patch file, no need to connect to Battle.net). However, 1.27a introduced the missing ambient sounds bug that didn't get resolved until 1.30.1
1.29.2 is a relatively bug-free single-player with widescreen support. 1.29.1 is also passable but has more bugs. Check the patch notes to see if you mind.
1.30.1 and on fix the ambient sounds issue. This is also the version supported by WC3Connect if you ever want to play online multiplayer including custom maps in a Battle.net-like environment, but outside Blizzard's official Battle.net
1.31.1 is the latest pre-Reforged version. This version added a lot of modding/world editor updates like LUA support.
PTR builds do not support LAN play

Tool to switch game versions: http://replaytool.warcraft3.org/

Find instructions and links for patches and individual client downloads here:
https://pastebin.com/CdskkiD9
https://pastebin.com/Wkbp8NeG