Hey there,
So just to let you know, game variant modding is possible and yes, I have some examples on my content browser (X3CXeX v3).
Have fun!
— GAME VARIANTS —
NEW - Weaponless Survivors [Infection]
No Weapon Start [Slayer]
Weapons Damages Disabled [Slayer]
Extended Motion Sensor (91m) [Slayer]
Slice Disabled (Distance: 0%, Speed: 500%) [Slayer]
Boom! (Grenades damage: 500%, Explosion radius: 500%, Knockback: 500%) [Slayer]
— TUTORIAL —
Requirements
Windows 10
Halo app + Halo 5: Forge
HxD (hex editor)
Fiddler (v4.6.x or upper)
A fresh Xbox LIVE account (recommended)
About 5-10 minutes
Tutorial
In this tutorial, I'll show you how-to set additional settings to a Slayer gametype by disabling weapons damages. Please note that variants are acting like patch files, so unfortunately (by now?) you can not mess with player's scale or whatever.
Start Halo 5: Forge through the Halo app, and launch Fiddler.
Open Fiddler Web Debugger and exempt Halo and Halo 5: Forge.
Go back to Halo 5: Forge and go to Multiplayer > Custom game > Game mode options > Player traits.
Scroll to Weapons section and set damages to 10% or whatever (should not be the default value, but let's use 10% here).
Keep an eye on Fiddler and save a copy of your game variant.
Find the save request (POST method) and save its body.
Open the saved file with HxD and look for AB 47 (hex values) in it.
Here we go. In the screenshot above, AB 47 CD CC CC 3D 00 00 represents our 10%.
Replace it by AB 47 00 00 80 BF 00 00, which is a 0%, and then select and copy all hex values.
Go back to Fiddler, unlock the save request for editing.
Switch to the HexView tab and replace the body (in black) by yours.
Reissue the request.
If everything was done correctly, the new POST request will return a 202 Accepted HTTP code.
Go back to Halo 5: Forge, load your new variants from your content browser and profit!
What now?
Your call! If you are looking for additional hex values, this might help you. Also, if you are an API developer, feel free to try cryptum-halodotapi (Advanced Halo 5 API wrapper which can be extended to other Halo games)!
Enjoy!
— X3CXeX (Zeny)