There are 5 ability scores in Star Control: Athletics, Combat, Piloting, Science, and Engineering. These ability scores are needed for certain Actions and for overcoming the challenges of planetary exploration. Doing so is called a “Skill Check” and requires rolling 2d6, adding the relevant ability score, and comparing to a difficulty class (DC).
All Crew are trained as a certain Profession: Marine, Pilot, Scientist, or Engineer. There are no Athletes. A Crew may reroll one die rolled during a Skill Check in a skill they are a Professional in. (Humans’ alien ability allows the option of rerolling both dice.)
At the start of the game, each Officer has Athletics 1, 0 in all other ability scores, and 1200 experience points to spend. Experience points can be stored for as long as a player wishes, and can be spent at any time. Yeomen have 2 in each ability score.
Experience Points (XP) are spent to raise ability scores. Raising an ability score costs a number of XP equal to 100x the value of the new ability score. Ability scores must be raised 1 value at a time. Thus, an Officer with a Piloting score of 2 must spend 300 XP to raise her Piloting skill to 3.
Destroying or capturing an enemy vessel grants all Officers 15 XP per Ship Size.