Fallout skills

Skill advancement
Each skill has its own skill level which is expressed as a percentage. Skill levels can be increased by allocating skill points earned from gaining levels. Skills can also be improved by reading specific books or completing quests within the game.

Raising a skill one percentage point costs one skill point. Tagged skills increase two percentage points per skill point. The maximum skill level is 200%.

Unlike perks, skill points can be left unspent and will remain, to be spent later. This could conceivably be useful in the event of a hurdle in the game of unknown type that would prevent further progress, e.g. a locked door. Any unspent skill points in excess of 99 are lost.

Effect of stats on skills
SPECIAL stats modify skills with a considerable bonus. The game keeps track of this bonus throughout the game, in real time. Any changes to stats, (e.g. chem effects, aftereffects and addiction effects or Mirrored Shades equipped) during the game add to or subtract from this modifier.

Effect of difficulty settings on skills

 * Combat skills are unaffected by difficulty settings.
 * Active and passive skills are lowered by 10 (%) when the difficulty is changed from "normal" to "hard".
 * Active and passive skills are raised by 20 (%) when the difficulty is changed from "normal" to "easy".