In
Fallout 4, every time you level up you're able to unlock or upgrade a perk, giving your character new abilities and proficiencies. The perks you're able to unlock are directly tied to your SPECIAL stats — each stat has 10 perks corresponding to the 10 points you're able to allot to that stat. The more points you have in a given stat, the "deeper" you're able to go: If you have eight strength points, you'll be able to choose between eight of Strength's assigned perks when you level up.
That means there's 70 base perks in
Fallout 4 to choose from, including some familiar faces — like a perk that increases the odds of "gibbing" your foes — and some newcomers. The series' Skills system is also tied into the tree, according to Howard. Most perks will also be upgradeable; with those additional ranks included, the progression system offers 275 things to unlock.
http://www.polygon.com/2015/7/24/90...ns-upgrades-special-customization-progression