Skills improve your efforts while on quests. Each skill point that you put in a skill is a reusable bonus that you add to contests related to that skill. Each skill gives its default contest type in parentheses. One XP buys you one skill point for any of the following skills:
Attack (P). Damaging opponents.
Deceive (MP). Misleading others. In combat, if you deceive an opponent, that opponent won't attack you on its next action (but it may attack an ally of yours).
Defend (P). Avoiding attacks.
Detect (M). Sensing or searching.
Magic (MP). Casting spells or other magical actions.
Move (P). Fleeing from opponents or traversing obstacles.
Persuade (MP). Changing Hostile NPCs to Indifferent, or Indifferent to Friendly. After persuading a Hostile NPC to Indifferent, you can try to make it Friendly, but if your contest is a Con, that NPC returns to Hostile.
Sneak (M). Avoiding detection. If you make a mental contest with Sneak, any NPCs in the next room do not notice (or attack) you if your contest is a Pro. Allies must also roll a Mental contest Pro to avoid detection.
Unlock (M). Using lockpicks or a skeleton key to open locked objects. If an opposing contest isn't given in the quest, your contest must exceed 18 (no Retry). Bolted, barred, or stuck doors cannot be unlocked. If you discover a trap, you can use this skill to circumvent or disable the trap, but a Con on such a contest means that you trigger the trap.