A high Perception grants a bonus to the Explosives, Lockpick and Energy Weapons skills, and determines when red compass markings appear (which indicate threats).

“A perceptive cowboy always knows when there’s a lit stick of dynamite nearby… or when a varmint’s sneakin’ up on him.”

Perception’s big draw is that it increases the distance as which you notice threats-red marks on your compass. Granted this is only useful for avoiding said threats, or ambushing/sneaking up on them. Still, if you are a ranged fighter, this is useful for letting you know where your enemies are before you engage. Yep, that’s right out of the old FAQ, and it holds true in New Vegas.

There are, however, a few changes in New Vegas that diminishes… or rather, replaces… the use of Perception in New Vegas. First, you can just toggle VATS to spot enemies far outside of your range to locate them, so long as you have a line of sight. With one side kick you get a perk that highlights enemies when you aim, and with another you get a perk that vastly increases your detection range. Both of these perks make having a high personal Perception score rather moot. Add into this the fact that with the new iron sights you can effectively snipe outside of VATS much easier… you don’t need a high Perception to find-and kill-enemies.

It still has its tactical uses to be sure, and more importantly it is a requirement for some perks, but you don’t need nearly as much Perception this time around. In fact, with the larger range of Perception you’ll get from one companion, you will see enemies on the compass much earlier than is useful. It doesn’t really do you much good to know that there are hostiles on the far side of a mountain, does it? Especially not until you find a way to reach that side of the mountain, in any case. The best thing Perception does is it allows you to get the Better Criticals perk. Without this you can really use it as a dump stat. That said, it’s hard to imagine why anybody would ignore +50% critical damage. Keep your Perception up at six (or five plus the Implant) to have access to this potent perk.

Start out with a base of five Perception.