Playing multiplayer on a pirated copy requires both players to use the same version of the game and identical crack files. Steamworks Fixes
are sometimes used as DLC unlockers, though they are primarily for legitimate Steamworks interactions. Common Multiplayer Connection Fixes
: These "fixes" (often from groups like REVOLT or Voksi) replace original game files with modified versions that spoof a legitimate Steam ID (often using "Spacewar") to allow connection through Steam servers with other users of the same fix. Virtual LAN (VPN) : Tools like Radmin VPN