Instructions
Select "Custom Games" on the main menu.
Go to "Games" and choose the game type ("Slayer," for instance).
Press "X" to enter the "Edit Game Options" screen. Select "Slayer Settings" followed by "Leader Traits."
Create a crazy multiplayer match by modifying "Shields and Health," "Weapons and Damage," "Movement," "Sensors" and "Appearance." For example, under "Movement," increase the player speed to 300 percent and gravity to 50 percent.
Exit to the "Options" screen and select "Weapons and Vehicles." Choose from "Primary Weapon," "Secondary Weapon," "Weapons on Map," "Grenades on Map," "Vehicle Set," "Indestructible Vehicles" and "Custom Powerup Traits." For instance, switch the primary weapon to the gravity hammer and the secondary to the rocket launcher.
Start the game to play with your modified settings for a crazy multiplayer "Halo 3" match.