Many role playing games base their player creation on an alignment axis similar to that pioneered by the venerable D&D franchise. This axis is a 3×3 grid that defines all of the potential character types used in the game.
If one were to put Good, Neutral, and Evil along one axis of the graph and Lawful, Neutral, and Chaotic along the other axis, one can see that this produces 9 distinct character types which can be used to differentiate everyone into a set of readily-understandable archetypes.
By assigning numerical values to each of these axis points on both the X and Y scale, one can then reduce character to a type of mathematical formulation to arrive at a basic character score. This can then be modified by circumstances, experience, health, etcetera in order to determine how someone reacts to the world and what they are capable of doing at that particular point in time.
