Point buy
From NWNWiki
NWN uses the point buy system to determine ability scores during character creation. The system is based on points rather than random dice rolls.
A character starts with an ability score of 8 in each of his six abilities, and then draws upon a pool of 30 points to raise these abilities. For example, a player might want to set his character's Strength to 10, and so he would spend two points to raise it from 8.
However, as an ability score is raised to exceptional levels, it becomes more expensive to raise further, as per the following chart: Raising an ability score from 8 to 16 costs 10 points, so be careful not to neglect the rest of a character's abilities when making one or two exceptional.
| Base Ability Score | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 |
| Cost | 0 | 1 | 1 | 1 | 1 | 1 | 1 | 2 | 2 | 3 | 3 |
| Total Cost | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 8 | 10 | 13 | 16 |
