In Darkmatter d20, the old classes of Combat Spec, Diplomat, Free Agent, and Techinical Operative are gone.  Replaced by Adepts, Civilians, Diplomats, Fighters, and Intellectuals, you will hopefully be able to fit your old character into one of the existing classes below.  You may note that there are subsections labeled Careers underneath each class.  Careers are specialties that go under each class.  Specialties can add new proficiencies, skills, or abilities to the basic class.  Every character of a class other than Civilian may choose one Career for free from the list below his class at 1st level.  Later, more Careers can be bought as feats, though only from the list of careers below that character's class.  GMs should feel free to allow characters to develop their own Careers, so that they can develop the type of character they want.

Adepts
Adepts are, for the most part, overlooked as a class in the real world.  These are the practitioners of the lost arts of magic and faith.  They are able to alter reality, and cause a variety of special affects through ceremonies or allegiances with otherworldly powers.  Adepts, like the other classes, receives a free career at 1st level.  However, they may not buy other careers as feats, or change classes to become a different kind of adept.
Hit Die: d4
Saving Throws: Average Fortitude, Average Reflexes, Good Willpower
Skill Points: 3
Class Skills: Concentration, Knowledge(arcane), Knowledge(religion)
Proficiencies: None
Careers:
Diabolist: Adds 3 Diabolism spells to class skills.  They may spend a feat to learn a new spell.
Enochian Sorcerer: Adds 3 Enochian Magic spells to class skills.  They may spend a feat to learn a new spell.
Hermetic Wizard: Adds 2 Hermeticism spells to class skills.  They may spend a feat to learn a new spell.
Monotheistic Priest: Adds 3 Monotheistic miracles to class skills.  They may spend a feat to learn a new miracle.
Shaman: Adds 3 Shamanic miracles to class skills.  They may spend a feat to learn a new miracle.
Houngan/Mambo: Adds 2 Voodoo hexes to class skills.  They may spend a feat to learn a new hex.

Civilian
Civilians make out the majority of people on earth.  They have a wide variety of skills, reflected in their customizeable skill list.  While not as combat-ready as the other classes, Civilians might actually be a useable character class for characters in Darkmatter, especially for those characters who wish to specialize in just a few specific skills.  Civilians, however, do not receive a free Career at 1st level.
Hit Die: d6
Saving Throws: Average Fortitude, Average Reflexes, Average Willpower
Skill Points: 3
Class Skills: Choose 2+ Int modifier skills as class skills, not including Firearms or Melee Weapons
Proficiencies: None

Diplomat
Diplomats are the master of the spoken word, people who are experts at negotiations and talking with others.  From con artists to military officers, Diplomats depend on their intelligence and charisma to get through life.
Hit Die: d6
Saving Throws: Average Fortitude, Average Reflexes, Good Willpower
Skill Points: 4
Class Skills: Bluff, Charm, Diplomacy, Gather Info, Intimidate, Sense Motive
Proficiencies: none
Careers:
Businessman: Add class skills Knowledge(economics) and Profession(business).
Con Artist: Add class skills Escape Artist, Move Silently and Prestidgitation.
Dilettante: Add class skills Knowledge(any three).
Facilitator: Add proficiency Pistols.  Add class skills Disguise, Escape Artist and Interrogate.
Lawyer: Add class skills Knowledge(law) and Interrogate.
Military Officer: Add proficiency Pistol, Rifle, Spear(for bayonets), and Submachine Guns.  Add class skills Firearms and Melee Combat.

Fighter
Fighters are the equivalent of Combat Specialists from the old Alternity rules.  As their name indicates, Fighters are those who fight for a living.  They include not only trained fighters like police officers or soldiers, but also those who are less dedicated to their craft, such as basic goons and brawlers.
Hit Die: d10
Saving Throws: Good Fortitude, Average Reflexes, Average Willpower
Skill Points: 3
Class Skills: Climb, Firearms, Intimidation, Jump, Melee Combat, Swim
Proficiencies: Clubs, Knives, Pistols, Rifles
Careers:
Assassin: Add any two proficiencies.  Add class skills Hide and Move Silently.
Martial Artist: Add class skills Balance, Jump and Tumble.
Militaman: Add class skills Craft(demolitions), Craft(traps), and Wilderness Survival.
Police Officer: Add class skills Interrogation, Search, and Sense Motive.
Security Specialist: Add proficiency Submachine Guns.  Add class skills Search and Spot.
Soldier: Add proficiencies Heavy Weapons, Spear (for bayonets), and Submachine Guns.  Also add class skills Spot and Wilderness Survival.
Woodsman: Add class skills Knowledge(nature), Search, and Wilderness Survival.

Intellectual
The replacement for Technical Operatives from the old rules, Intellectuals are those who favor brain over brawn.  They include all manner of academicians, doctors, and scientists. 
Hit Die: d4
Saving Throws: Average Fortitude, Average Reflexes, Good Willpower
Skill Points: 6
Class Skills: Gather Info, Knowledge(any two), Perform(writing), Search, Use Computer
Proficiencies: None
Careers:
Doctor: Add class skills First Aid and Knowledge(medical).
Engineer: Add class skills Craft(specific), Electronics and Mechanic.
Field Guide: Add proficiency Rifles.  Add class skills Knowledge(nature) and Wilderness Survival.
Forensics Expert: Add class skills Knowledge(medical), Knowledge(toxicology) and Spot.
Hacker: Add class skills Craft(programs) and Knowledge(computers).
Mechanic: Add class skills Electronics and Mechanic.
Pilot: Add class skills Pilot(specific) and Mechanic.
Psychologist: Add class skills Diplomacy, Interrogate and Knowledge(psychology).
Scientist: Add class skills Knowledge(science) and Knowledge(specific).

Rogue
Descended from the Free Agents of the original Alternity rules, Rogues are those who live by their wits and intelligence.  Rogues include a wide variety of occupations, from criminals to spies.  The broadest of classes, Rogues are essential to any Darkmatter group, as they are the ones who specialize in invetigation, stealth, and subterfuge.
Hit Die: d8
Saving Throws: Average Fortitude, Good Reflexes, Average Willpower
Skill Points: 4
Class Skills: Balance, Bluff, Escape Artist, Hide, Move Silently, Prestidgitation, Sense Motive, Spot, Tumble
Proficiencies: None
Careers:
Burglar: Add class skills Climb, Electronics and Open Locks.
Field Agent: Add proficiency Pistols.  Add class skills Disguise, Gather Info and Interrogation.
Investigator: Add class skills Gather Info, Interrogation, Search, and Spot.
Journalist: Add class skills Gather Info, Interrogation, Perform(oratory) and Perform(writing).

The rules above are just a basic guide.  Feel free to develop your own Career specialties or other new aspects of the above Classes.  If you have any questions, suggestions, or Careers you'd like to see posted here, please e-mail us.