Each species has a total of starting attribute dice pool to spend of as well as minimum and maximum dice values that may be assigned to a given attribute.
You can break up Attribute dice into smaller units as long as you do so within the min/max allowed for each attribute. Each die code has three levels of pips: 0, 1, 2. The die progression always follows this pattern: 1D, 1D+1, 1D+2, 2D, 2D+1, 2D+2, 3D and so on. 3 pips equal 1D in regard to Attributes.
Biotics is the only attribute that does not begin with a minimum value for most species. The Asari have an innate Biotic ability from birth so begin with 1D while all other species begin with Biotics at 0.
Also note that Biotics will not show up under the Attributes section of the +sheet. This was done for ease of tracking chosen Biotic powers.
The six base attributes are defined as follows:
How physically articulate your character is, including his eye-hand coordination and agility.
Physical power and ability to resist damage.
Prowess at operating mechanical equipment like vehicles, shields, starships, and sensors.
Overall intelligence, "common sense" and academic knowledge.
Awareness of onself and surroundings, including the ability to interact with others.
The ability to manipulate, repair, and modify technology.
Attributes In Practical Use
Attributes reflect the foundations of how your character is able to do all of the things that he or she can do. A Cerberus Phantom would need greater dexterity, a skycar mechanic would need greater Technical aptitude, while a professor or galactic scholar would benefit from a greater Knowledge score. Each attribute's score directly affects the skills you choose. Rolls are comprised of Attribute die value + Skill level + specialization level (where appropriate) + any other pertinent bonuses from situation, equipment or mods.
For example, a human Mechanic might have a Technical score of the max allowed for humans, 4D. She might have purchased up to the CharGen skill point cap of 9 for her Repair skill, and purchased Specialization of Repair: Skycar to its CharGen maximum point cap of 9.
To roll for repairs she would roll a total of: 4D+9(repair)+9(Repair: Skycar Specialization).
The higher your Attribute the better your overall roll results spread will be.
e.g. The minimum result from that roll would be 22. The maximum before - rerolling the Wild Die - would be 42.