Fallout: New Vegas Perks

General information
Unlike Fallout 3, in Fallout: New Vegas you gain perks every two levels. There are 88 regular perks, 8 companion perks, 16 challenge perks and other unknown amount of special perks.

Challenge perks can be unlocked as well by fulfilling certain requirements. To counter how easy it was to max out the player's skills in Fallout 3, most of the skill-boosting perks from Fallout 3 have been removed and replaced.

Companion perks
Fallout: New Vegas is not the first Fallout game to introduce the concept of companions having perks, but is the first to have perks that affect the party as a whole.