A Splitscreen Mod for Halo the Master Chief Collection

Showcase

Splitscreen in Every Game	LAN Mutliplayer Support
Camera Tool (H3)	Object Browser (H3)
8 Players Campaign	Splitscreen With Mod (By Priception)

Features

• Splitscreen (all games)
• "Xbox 360" Menu (controller-friendly, toggled with F4/Left Stick Click + Start)
• Advanced Menu (for greater customization, toggled with F1)
• Camera Tool (H3)
• Object Browser (H3)

Installation

Good news! We now have a launcher for quickly setting up the mod. You can find the repository here. For a quick guide, watch this YouTube video: https://www.youtube.com/watch?v=E_0IjFBD2pI&t=30s

Manual Installation

Make sure you have the latest Microsoft Visual C++ Redistributable installed.

Download the latest stable build from the Releases page.

Place the DLL into the "Halo The Master Chief Collection\mcc\binaries\win64" directory and launch the game with EAC off.

For Running on Steam Deck/Linux, add the following command in the Steam Game Launch Options:

WINEDLLOVERRIDES="WTSAPI32=n,b" %command%

Works with any Proton version (Proton 9.0, Proton Experimental, Proton GE, etc.)

1. Configure the game:

   • Right-click MCC → Properties → Compatibility
   • Enable "Force the use of a specific Steam Play compatibility tool"
   • Select any Proton version (Proton 9.0, Experimental, or Proton GE all work)

2. Set launch options: Add the following to Steam Launch Options:

   WINEDLLOVERRIDES="WTSAPI32=n,b" %command%
   

3. Controller Setup (Important for non-Xbox controllers):

   • For 8BitDo and other third-party controllers, enable Steam Input for the controller
   • Go to Steam → Settings → Controller → Enable "Xbox Configuration Support"
   • This allows Steam to translate your controller inputs to XInput, which MCC and AlphaRing expect
   • Without this, some buttons (like A or stick clicks) may not be detected

Note: Tested on Batocera Linux with the unofficial Batocera add-ons Steam client.

Usage

Toggle menu: F4 or Controller Back + Controller Start

To navigate using Controller use the Right Stick to move the mouse and RB to click.

When the menu is open, game input is disabled.

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Building from Source

Prerequisites

• Visual Studio 2022 Build Tools
• CMake 3.27+

Build Commands

# First time setup
mkdir build && cd build
cmake .. -G "Visual Studio 17 2022" -A x64

# Build
"C:/Program Files (x86)/Microsoft Visual Studio/2022/BuildTools/MSBuild/Current/Bin/MSBuild.exe" WTSAPI32.vcxproj -p:Configuration=Release -p:Platform=x64

Output: build/Release/WTSAPI32.dll

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Credits

• Original AlphaRing: WinterSquire
• Controller Binding and Proton Fixes Fork: kirklandsig
• Assembly for the tag group research.
• Blender for the bezier curve calculation.
• Priception for adding UI controller support and helping with the interface and crash issue.