Intelligence
From AoP Wiki

Intelligence is the fifth of the seven Specials a character can have a set amount of points in. Intelligence is important, if you want to receive a lot of Skill Points per Level up, making your character stronger in Skills, or more versatile. It also increases your Base Critical Chance.
Each point of Intelligence adds
- +2 Skill Points per Level
- +2% Base Critical Chance (And thus +2% Aimed Critical Chance).
Additionally, each point of Intelligence raises the following starting value of Skills:
- +1% Energy Weapons
- +1% Close Combat
- +3% First Aid
- +3% Doctor