We have posted the USX:Apocalypse Campaign Rules in our forums here
http://rafm.com/phpbb3/viewtopic.php?f=12&t=612Here is a more detailed listing of what is provided in the Campaign Rules.
Skills
Machines
Machine Special Rules
Special Ammo Rules: TCR Ammo, DS Shells, EMP Grenade
Campaign Rules Force Lists
Purchasing New or Replacement Models
Strongholds - Stronghold Component Chart
Upgrades
Creating a World
The Campaign Game - Turn Sequence, Movement on the Campaign Map
Choosing a Scenario - Prisoners
Character Retirement, Character Advancement, Level Advancement, Skill Advancement, Statistic Maximums
Generating Income
Trade Center Sites - Random Events
The Factions (lists, point costs and advancement charts)
Remnant Forces
SWAT
The Iron Brethren (Brotherhood of Steel)
Mi-go (for that Cthulhu Element)
Elder Things
The Hasturites
The Dragonflies
Cultists
Pyramid Corporation
Survivors – Modern Day Heroes
Scenarios