Star Wars: Knights of the Old Republic/Alignment

Choices made by main player characters throughout the game can affect their alignment to the light or dark side of the Force. This alignment has a hidden numerical value between 0 and 100, representing the extremes of dark side mastery and light side mastery respectively. Main player characters begin the game at 50, with dark side actions subtracting from that value and light side actions adding to it.

Alignment of party members is static, and does not change as a result of their own actions or those of the main player character. However, comments on the choices of the main player character will differ depending on the alignment of the party member.

Appearance
When viewing character models on the character screen an arrow will indicate their position on the meter to their left, while an icon will appear on the status bar to their right when light side or dark side mastery is achieved. The background and their facial expressions and stances also indicate where they are on the spectrum of good and evil:



Main player character portraits also change as they progress towards the dark side:



Equipment
Certain items cannot be equipped unless a character has progressed beyond a certain threshold to either side: items restricted to the dark side cannot be equipped unless a character’s alignment is 0-40, while those restricted to the light side cannot be equipped unless it is 60-100:

Force powers
Some Force powers are inherently light or dark in nature, and cost more Force points to use if a character is of opposing alignment:

The alignment value thresholds in the manual are not entirely accurate (those above are derived from the game itself). Light side power costs increase the further to the dark side a character is (and vice versa):

Use of Force powers of opposing alignment does not affect a character's alignment.

Mastery
Mastery bonuses are only applied to the main player character in the PC version of the game, and vary according to Jedi class and alignment:

Mastery bonuses are not permanent; they are only applied when alignment is at either extreme of 0 (dark side) or 100 (light side). A dark side action will result in a light side mastery bonus being lost (and vice versa), although it can be regained with appropriate action.

The dark side mastery bonus for a Jedi Guardian does not apply when unarmed, but it does apply when equipping any kind of weapon (whether ranged, melee or lightsaber).