Important note: "Free" here refers to playing offline against bots (Combat Training) or over LAN (no internet required after setup). You still need a legitimate copy of the game to play legally. This guide does not promote piracy.
If you have multiple PCs on the same local network (no internet required after setup): Important note: "Free" here refers to playing offline
Steps:
Pros: Play with real people, offline, no ping issues.
Cons: Requires multiple PCs and game copies. Pros: Play with real people, offline, no ping issues
You cannot legally get Black Ops 1 for free permanently, but you can play for free temporarily: Pros: Play with real people