The D20 - D6 Conversion System
Converting characters from the D20 system into the D6 system is largely based on taking the formula found in the back of the WotC core rule book and working backwards. It's not a 100 percent accurate science, but it's close enough for government work. Simply connect the dots and season to taste.

Step one - Convert attributes
For my conversions, I use the highest of whichever attribute is appropriate

D6	D20
Dexterity	Dexterity
Knowledge	Intelligence/Charisma
Mechanical	N/A
Perception	Wisdom/Charisma
Strength	Strength/Constitution
Technical	Intelligence/Wisdom

Since there is no corresponding game mechanic for the D6 attribute Mechanical, I leave this one until last. After converting all of the other attributes, total them up. Anything shy of 18D is what I use for the Mechanical attribute.

D20 Score	D6 Attribute
8	1D
9	1+1
10	1+2
11	2D
12	2D+1
13	2D+2
14	3D
15	3D+1
16	3D+2
17	4D
18	4D+1
19	4D+2
20	5D
21	5D+1
22	5D+2
23	6D

and so on . . .

Step Two - Skill Conversion
For this step, simply follow the chart and convert the D20 skills to their WEG counterpart. Where a corresponding skill does not exist (such as say - craft: blaster), simply either make up the D6 skill or drop it from the character all together.

D20	D6
Appraise	Value
Astrogate	Astrogation
Bluff	Con
Climb	Climbing / Jumping
Computer Use	Computer Programming / Repair
Craft	N/A
Demolitions	Demolitions
Diplomacy	Persuasion
Disable Device	Security
Disguise	N/A - although a D6 equivalent would be easy enough to create.
Entertain	N/A
Escape Artist	N/A
Forgery	Forgery
Gather Information	Investigation or Streetwise, depending on character concept
Handle Animal	Beast Riding
Hide	Hide
Intimidate	Intimidation
Jump	Climbing/Jumping
Knowledge	Scholar: [SKILL]
Listen	Search
Move Silently	Sneak
Pilot	Piloting, Gunnery, Starship Shields, and Vehicle Operation
Profession	N/A
Read/Write Language	Languages
Repair	Repair skill appropriate to character concept
Ride	Beast Riding
Search	Search
Sense Motive	N/A (con, perhaps?)
Sleight of Hand	Pick Pocket
Speak Language	Languages
Spot	Search
Survival	Survival
Swim	Swimming
Treat Injury	First Aid
Tumble	Dodge

Step Three - Rank Conversion
The conversion of skill ranks into dice is a simple matter - each rank equals one pip. So, a +6 intimidation converts over to +2D in the D6 system, and a +5 Disable Device is a 1D+2 Security. Simply add this into the base D6 attribute for the final score.

The various languages and the Read/Write Language skills are a bit different. For each language known (spoken or written) translates until +1D in the D6 Language skill.

Weapon skills are a bit different - since there is no individual weapon skill in the D20 system. In that case, simply use the To-Hit bonus and apply that the appropriate combat skills (as determined by the Weapon Feats). So, a +7/+2 ranged bonus turns into a 3D skill (probably in Blaster). In addition, the class based defense score converts over to dodge - IE, a +9 class bonus is a 3D dodge.

Step Four - Feat Conversion
The feat conversion is fairly straightforward and direct. There are only a few feats that don't have a corresponding D6 skill somehow. Simply add the converted Die directly into the appropriate skill.

D20 Feat	D6 Equivalent
Acrobatic	+1D each to Climbing/Jumping and Dodge
Alertness	+2D to Search
Ambidexterity	No Penalty with the character's off hand
Animal Affinity	+1D to Beast Riding
Armor Proficiency (light)	No comparable D6 game mechanic
Armor Proficiency (medium)	No comparable D6 game mechanic
Armor Proficiency (heavy)	No comparable D6 game mechanic
Armor Proficiency (powered)	+1D to Powersuit Operation
Athletic	+1D to both Climbing/Jumping and Swimming
Blind-Fight	No comparable D6 game mechanic
Cautious	+1D to both Demolition and Security
Cleave	+1D to Melee Weapons OR Lightsaber
Dodge	+1D to Dodge
Endurance	+1D to Stamina
Exotic Weapon Proficiency	+1D to specified weapon
Expertise	+1D each to Melee Weapons and Melee Parry
Fame	No comparable D6 game mechanic
Force Sensitive	Character is now Force Sensitive
Frightful Presence	+1D to Intimidation
Gearhead	+1D to any one Technical skill
Great Cleave	+1D to Melee Weapons OR Lightsaber
Great Fortitude	No comparable D6 game mechanic
Heroic Surge	No comparable D6 game mechanic
Improved Initiative	+1D to Perception for Initiative ONLY
Improved Two Weapon Fighting	+1D to Melee Weapons OR Melee Parry
Infamy	No comparable D6 game mechanic
Iron Will	+1D to Willpower
Lightning Reflexes	+1D to Dodge
Low Profile	No comparable D6 game mechanic
Martial Artist	+1D each to Brawl and Brawling Parry skills.
Mimic	+1D to Con
Multishot	+1D to any one ranged weapon skill
Nimble	+1D to Pick Pockets
Mobility	+1D to Dodge
Persuasive	+1D to Persuasion
Point Blank Shot	+1D to any one ranged weapon skill
Power Attack	+1D to Melee Weapons OR Lightsaber
Far Shot	+1D to any one ranged weapon skill
Precise Shot	+1D to any one ranged weapon skill
Quick Draw	No comparable D6 game mechanic
Quickness	+1D to Brawling Parry OR Melee Parry
Rapid Shot	+1D to any one ranged weapon skill
Run	+1D to Running
Shot on the Run	+1D to any one ranged weapon skill
Sharp-Eyed	+1D to Search
Skill Emphasis	+1D to specified skill or equivalent
Spacer	+1D to both Astrogation and one Piloting skill
Spring Attack	+1D to Dodge
Starship Dodge	+1D to any one Piloting skill
Starship Operation	+1D to any one Piloting skill
Stealthy	+1D to Sneak
Toughness	No comparable D6 game mechanic
Track	+1D to Search: Tracking skill specialization
Trustworthy	+1D to both Persuasion and Investigation
Two-Weapon Fighting	+1D to both Melee Weapons and Melee Parry
Weapon Finesse	+1D to Melee Weapons, Lightsaber OR Brawling
Weapon Focus	+1D to any weapon skill specialization
Whirlwind Attack	+1D to Melee Weapons

Weapon Group Proficiency -

Blaster Pistols	+1D to Blaster weapon skill
Blaster Rifles	+1D to Blaster weapon skill
Heavy Weapons	+1D to Blaster Artillery OR Missile Weapons weapon skill
Primitive Weapons	+1D to Bows OR Thrown Weapons weapon skill
Simple Weapons	+1D to Melee Weapons weapon skill
Slugthrowers	+1D to Firearms weapon skill
Vehicle Weapons	+1D to Vehicle Blasters weapon skill
Vibro Weapons	+1D to Melee Weapons weapon skill
Zero-G Combat	N/A

Step Five - The Force
Converting the Force between the two systems is just the same as the rest of the conversion process, but a whole lot looser. Fortunately for the most part, D6 Force powers do have direct counterparts in the D20 system. However the D20 version is broken down by individual abilities, rather than the all encompassing Control, Sense and Alter skills. This forces more of the final decisions up to the GM doing the conversion.

To determine the D6 characters' base Force die codes, simply give them one Die per Control, Sense and Alter feats - in their respective D6 die code, of course. Increase each of these die codes by one pip for each rank the D20 character has in that Force skill. For example: the D20 version of Jedi Bob has the Sense and Alter feat, plus the Force skills Move Object +4, Force Push +4 and See Force +2. This means that the D6 Jedi Bob has a Sense of 2D+1 and an Alter of 3D+2. Any skill that uses all multiple force powers (such as projective telepathy), divide the pips up amongst the D6 die codes.

Translating the Force Feats into die codes follows the same principle. For each Force Feat, add a full die into the respective D6 skill. For example a Force Whirlwind feat adds +1D to the Alter skill, and Force Lightning feat adds +1D to Control and Alter.

The last step is to ensure that the character has all the prerequisite Force powers for each of the new Force powers. If the newly converted character doesn't have them, simply add the prerequisite without any additional bonuses to the existing Force die codes.

D20 Force Skill	D6 Equivalent
Alchemy	Scholar: Alchemy
Affect Mind	Affect Mind
Battlemind	Lightsaber Combat OR Combat Sense
Control Mind	Control Mind
Drain Knowledge	Memory Wipe
Empathy	Receptive Telepathy
Enhance Ability	Enhance Attribute
Enhance Senses	Magnify Senses
Farseeing	Farseeing
Fear	Waves of Darkness
Force Defense	Force of Will
Force Grip	Telekinetic Kill
Force Push	Telekinesis
Force Stealth	Enhance Attribute
Friendship	No comparable D6 game mechanic
Heal Another	Accelerate Anothers Healing, Control Anothers Disease, Control Anothers pain, return another to consciousness, Transfer Force
Heal Self	Accelerate Healing, Reduce Injury, Control Disease, Control Pain, Detoxify Poison, Resist Stun
Illusion	Doppleganger
Move Object	Telekinesis
See Force	Sense Force Potential, Life Detection, Life Sense, Sense Force
Telepathy	Projective Telepathy
Transfer essence	Transfer Life

D20 Force Feat	D6 Equivalent
Alter	Alter
Burst of Speed	Enhance Attribute
Control	Control
Deflect Blasters	Lightsaber Combat
Dissipate Energy	Absorb/Dissipate Energy
Drain Force	Drain Life Essence
Force Lightning	Force Lightning
Force Mastery	+1D to any Force skill
Force Mind	Enhance Another's Attribute
Force Whirlwind	Telekinesis
Hatred	Force Scream
High Force Mastery	+1D to any Force skill
Knight Defense	Lightsaber Combat
Knight Mind	Enhance Another's Attribute
Knight Speed	Enhance Attribute
Lightsaber Defense	Lightsaber Combat
Master Defense	Lightsaber Combat
Master Mind	Enhance Another's Attribute
Master Speed	Enhance Attribute
Prolong Force	No comparable D6 game mechanic
Rage	Rage
Sith Sorcery	No corresponding Force Power
Sith Sword Defense	No corresponding Force Power
Sith Sword Expert Defense	No corresponding Force Power
Sith Sword Mastery	No corresponding Force Power
Sense	Sense
Summon Storm	Force Wind
Throw Lightsaber	No corresponding Force Power