Star Wars: Knights of the Old Republic/Experience

Main player characters receive experience points (XP) for the following:
 * Advancing quests
 * Killing enemies
 * Using some skills (particularly Computer Use and Repair)

Kills
Experience received from kills varies depending on the Challenge Rating of the enemy killed and your main player character's experience level (not character level):

For example, if your main player character is currently level 2 but you have enough experience to level up to 8, when you kill an enemy with Challenge Rating 5 you receive 150 XP, not 450 XP (so you cannot level up more quickly by saving levels).

You receive experience from enemies killed by any allies, even if those allies are not members of your party (for example, repaired droids). However, this isn't recorded in Feedback.

Computer Use
You receive experience from many operations involving Computer Use throughout the game, and you also receive it from enemies killed as a result of these operations (although you aren't notified of it, it is recorded in Feedback).

Repair
You receive experience from many operations involving Repair throughout the game, and you also receive it from enemies killed by repaired droids (although you aren't notified of it, and it isn't recorded in Feedback).

Stealth
As far as is known, you only receive experience for using Stealth once in the entire game: 300 XP for sneaking past three Sith on the Endar Spire's Starboard Section.

Level up
Receiving experience allows characters to gain levels. Experience needed for next level = 1000 * current level:

Characters can gain levels up to maximum level 20. Party members gain 80% of the experience gained by the main player character, regardless of whether or not they are in the current selection: for example, upon becoming level 20 with 190,000 experience, party members have 152,000 experience (so they are only level 17 since 153,000 is needed for level 18). Thus the main player character needs at least 237,500 XP for party members to gain level 20.

Saving levels
For all but the main player character, whenever enough experience is received to level up, doing so as soon as possible is recommended. However, the main player character starts as one class and later chooses a Jedi class, so the more levels gained with the starting class, the less can be gained with the Jedi class (and vice versa).

You're obliged to level up once to progress beyond the bridge of the Endar Spire, but after you've gained level 2 you don't have to level up any further, even once you've received enough experience to gain multiple levels. Before you choose a Jedi class you'll typically have received enough experience to gain level 8 at most; even if you're able to gain higher level with your starting class, this isn't recommended as level < 12 Jedi are not granted Master Sense (+2 Defense) or the highest level of their class feat.

Since the maximum level is level 20, the choice is normally somewhere between level 2-8 starting class and level 12-18 Jedi class. Since saving levels can make Taris (much) more challenging, remaining at level 2 isn't recommended except for experienced players who choose to become a Jedi Consular (since this gives them more Force powers earlier and in total, and more Force points to use them for longer and regenerate more out of combat).

Level 5 starting class and level 15 Jedi class is a popular choice, since all starting classes can select a feat at level 5 and all Jedi classes can select one at level 15. However, more experienced players may choose differently depending on a number of factors.

Vitality
Vitality of main player characters at level 20 depends on starting class, Jedi class and the level at which they become a Jedi:

These totals increase by 20 with Toughness and again with Master Toughness, and are further modified by 20 * CON.

Saves
Saves of main player characters at level 20 depend on starting class, Jedi class and the level at which they become a Jedi:


 * Level 20 Jedi Guardian or Jedi Sentinel


 * Level 20 Jedi Consular

These totals are further modified by CON for Fortitude, DEX for Reflex and WIS for Will. They're also increased by the Conditioning feats, the light side Force Aura and Force Valor Force powers and items.

Force
Force points of main player characters at level 20 depend on starting class, Jedi class and the level at which they become a Jedi. The following totals include 40 Force points from the Force Sensitive feat:

These totals are further modified by 20 * WIS+CHA.

Skills
Total skill points main player characters can spend by level 20 depend on Intelligence, starting class, Jedi class and the level at which they become a Jedi:


 * Level 20 Jedi Guardian or Jedi Consular


 * Level 20 Jedi Sentinel

Force powers
Total Force powers main player characters are granted by level 20 depend on Jedi class and the level at which they become a Jedi:

Feats
Feats granted to each class may influence the level at which you choose a Jedi class:

Total feats main player characters can select by level 20 depend on starting class, Jedi class and the level at which they become a Jedi: