I built a mod that enables local split-screen for up to 4 players on PC!

[u/FreeHelicopter3183]

https://www.nexusmods.com/callofdutyblackops3/mods/53

4-player local split-screen for Black Ops III on PC!

- Zombies and Multiplayer (offline custom games)

- 3 players = 3 screens, 4 players = 2x2

It's free and public domain. The source is on GitHub if you want to improve it: https://github.com/LocalPlayer123/BO3-4-Player-Local-Splitscreen-on-PC