You have five core skills. Core skills increase with use, although the higher they get the slower they increase. You can use boosts to raise them faster (see ‘help boost’), but they must still be used in order to raise them. The highest a skill can get to is 100, or your Age, whichever is higher.
Combat represents your general fighting ability. It goes up as you fight, and is added to all of your weapon skills when calculating their bonuses.
Athletics represents your physical fitness. It is applied to your health as a percentage (see ‘help health’) and also increases your movement speed.
Riding represents your skill at riding mounts. While mounted this skill works like a weapon skill for your feet, and like Athletics for movement speed.
Meditate works in the same way as Combat, but is applied to magic colours.
Focus is applied as a percentage modifier to your mana (see ‘help mana’).