The following skills may be grouped together. I generally allow players to choose up to half the number of levels as skills in the specific skill cluster listed under "Subsequent Term Skills" in their profession. Thus, if the skill cluster has six skills, the player may choose three levels in any combination of skills in the skill cluster. In the case of fractions, round up.

There is some overlap between certain clusters.

Acrobat Skill Cluster

Acrobatics Climbing Escape Skill Jumping
Stealth Thrown Weapon    

Aircraft Skill Cluster

Pilot (Fabric Wing) Pilot (Fixed Wing) Pilot (Glider) Pilot (Jet)
Pilot (Multiengine) Pilot (Rotary Wing) Pilot (Spacecraft)  

Animal Handling Skill Cluster

Animal Handling and Training Farming Riding  

Archaic Weapons Skill Cluster

Archery Thrown Weapon    

Artillery Skill Cluster

Archaic Artillery Forward Observer Heavy Artillery  

Artisan Skill Cluster

Carpenter Jeweler Mason Metallurgy

Charm Skill Cluster

Act/Bluff Carousing Persuasion Recruiting

Crime Skill Cluster

Escape Skill Forgery Intrusion Pickpocket

Determination Skill Cluster

Leadership Streetwise Willpower  

Economics Skill Cluster

Admin/Legal Business Bargain Business

Engineer Skill Cluster

Civil Engineer Combat Engineer Construction Demolitions

Explore Skill Cluster

Cartography Climbing Navigation Scrounging
Survival Swimming    

Fine Arts Skill Cluster

Act/Bluff Dance Disguise Music
Painting Sculpture Song  

Gun Combat Skill Cluster

Autogun Pistol Rifle  

Heavy Weapons Skill Cluster

Autogun Grenade Launcher Tac Missile  

Helm Operations Skill Cluster

Ship Helm Operations Submarine Helm Operations  

Interaction Skill Cluster

Bargain Instruction Interrogation Language

Medical Skill Cluster

Biology Medical (Diagnosis) Medical (Surgery) Medical (Trauma)

Melee Skill Cluster

Armed Martial Arts Unarmed Martial Arts    

Perception Skill Cluster

Blind Fighting Cryptography Observation Psychology
Research Scrounging Stalking Tracking

Personal Transport Skill Cluster

Bicycle Long Distance Marching Parachute Snow Skiing

Physical Science Skill Cluster

Biology Chemistry Farming Genetics
Geology Meteorology Physics  

Social Science Skill Cluster

History Instruction Language Persuasion
Psychology Research    

Tactics Skill Cluster

Tactics (Air) Tactics (Ground) Tactics (Ship)  

Technician Skill Cluster

Aircraft Mechanic Computer Cryptography Electronics
Gunsmith Machinist Mechanic Metallurgy
NBC Specialist Reactor Operations Warhead  

Vice Skill Cluster

Bribery Disguise Gambling Streetwise

Vehicle Skill Cluster

Ground Vehicle (Motorcycle) Ground Vehicle (Snowmobile) Ground Vehicle (Tracked) Ground Vehicle (Wheeled)

Vessel Skill Cluster

Vessel Use (Boat) Vessel Use (Hovercraft) Vessel Use (Ship)