I finetuned the calculations of my Array Point-Buy System to treat the tertiary ability, in addition to the primary and the secondary. The finetuning has little impact on the value of an array, and is mainly for scenarios that rarely happen, where the tertiary ability seems one score point better than expected. But it adds a greater degree of precision.
Haldriks Array Point-Buy System
Score
|
Primary Ability
Cost =
Bonus ^2.3
|
Secondary
Ability
Cost =
Bonus ^2
|
Tertiary
Ability
Cost =
Bonus ^1.5
|
Peripheral
Abilities
Cost =
Bonus
|
20
|
40.5
|
25
|
11.2
|
5
|
19
|
27.1
|
17.6
|
8.6
|
4.2
|
18
|
24.3
|
16
|
8
|
4
|
17
|
14.5
|
10.2
|
5.7
|
3.2
|
16
|
12.5
|
9
|
5.2
|
3
|
15
|
6.1
|
4.8
|
3.3
|
2.2
|
14
|
4.9
|
4
|
2.8
|
2
|
13
|
1.5
|
1.4
|
1.3
|
1.2
|
12
|
1
|
1
|
1
|
1
|
11
|
|
|
|
0.2
|
10
|
|
|
|
0
|
9
|
|
|
|
−0.8
|
8
|
|
|
|
−1
|
7
|
|
|
|
−1.8
|
6
|
|
|
|
−2
|
5
|
|
|
|
−2.8
|
4
|
|
|
|
−3
|
3
|
|
|
|
−3.8
|
The table has a number of interesting properties. For example, a 0-Point Buy can purchase an exactly average array (11 11 11 10 10 10). Also, the exponents of the bonuses are a value to the power of about the Golden Ratio (0.618), a surprise.
When using the table, remember, the Primary Ability is your highest ability. The Secondary Ability must be equal to or less than the Primary. The Tertiary ability must be equal to or less than the Secondary, and so on down the array.
In an other thread, you can find a friendlier simpler version of the above table, specifically for the 12.6-point cost of the Standard Array (15 14 13 12 11 10).
