Power Armor: The Bespoke Robot Suit Of The Commonwealth
Power armor is one of the biggest changes to come to Fallout 4, even moreso than the settlement system and the New England accents. Just by climbing into your power armor rig, you gain huge bonuses to damage resistance, strength, carry weight, and the total removal of falling damage. Even if you never alter your armor at all, it still gives you a huge advantage over your enemies. And in the Commonwealth, you'll find a lot of enemies.
If you put in the effort and learn how to use your power armor to its full potential, even a low endurance, low strength build can tear through the Commonwealth like the killing machine you've always wanted to be.
Any build with any set of SPECIAL attributes can get some benefit out of power armor. However, there are a few perks that are needed to get the most out of your power armor. And each perk in Fallout 4 has a SPECIAL requirement.
A high strength build is highly compatible with power armor. If you want to be able to smash off a deathclaw's head with your bare hands--and who doesn't--you'll find the strength tree will suit you just fine.
The Strength tree has the most important perk for power armor users: Armorer. This is the most fundamental trait for altering and improving your power armor. You only need a Strength of 3 to unlock the Armorer perk, making it easily accessible even for non-strength focused builds.
A strength of 4 or above will give you access to the Blacksmith perk, which will let you make some seriously damaging mods to the arms of your power armor. If you don't plan on using melee or unarmed attacks, this perk is one to skip.
With a strength of 10 or above, you'll gain access to the Pain Train perk. This lets you smash your way through enemies by sprinting into them. It's a lot of fun, and effectively turns you into an irradiated wrecking ball, but it's hardly necessary.
There are no Perception perks that relate directly to power armor. There are, however, a number of perks that relate to general combat effectiveness and defense. Which Perception perks you take, if any, will depend on your combat style.
Power armor naturally gives a good amount of damage resistance. When coupled with a number of Endurance perks, you can make yourself practically bulletproof. The Aquaboy/Aquagirl perk is one that a lot of people consider useless, but it has one big benefit for power armor users.
Power armor sinks to the bottom of any body of water. And while power armor lets you survive underwater for longer than usual, you can still drown. And when you start drowning in power armor, your only real choice is to either reload, abandon your power armor frame, or quit the game forever. With the Aquaboy/Aquagirl perk, you are no longer capable of drowning. This means that you can walk around underwater for as long as you want, Pirates of the Caribbean style.
There aren't really any charisma perks that relate to power armor. However, a high-charisma build will allow you to more easily purchase the expensive components that are required to build a cherry set of power armor.
There are a number of Intelligence perks that are practically required for a good set of power armor. The Scrapper perk is useful for scaring up the components you'll need for your suit, although it's not really required. It only requires an Intelligence of 5.
The Science! perk, which requires an intelligence of 6, is needed to build most of the fancier power armor mods.
The Nuclear Physicist perk requires an Intelligence of 9 or above, but it is extremely helpful. Not only does it make your fusion cores last longer, but at the third rank of the perk, you gain the opportunity to shoot spent fusion cores out, engulfing surrounding enemies in nuclear fire.
There aren't any Agility perks that relate directly to power armor usage. Depending on your combat build, though, you'll need a high Agility score. A high Agility score gives you huge bonuses to sneaking, as well. While sneaking in power armor is generally not the best idea, having the option gives you a great deal of flexibility.
There aren't any Luck perks that relate directly to power armor usage, although both the increased caps and the quicker and more powerful criticals make Luck useful all around.
Strengths and Weaknesses
Power armor is mostly strengths. On top of the increased strength, hit points, damage resistance, radiation resistance, and complete immunity to fall damage, and how tall it makes you look, there are a number of other benefits. The various mods and upgrades can give a number of other benefits, some damage based, some of which improve your SPECIAL scores.
There are a few drawbacks to power armor, however.
First, power armor requires fuel, in the form of fusion cores. If you wear your power armor all the time, you're going to eat through fusion cores. Fusion cores can be found around the Commonwealth, bought at vendors for several hundred caps a piece, or stolen from other power armor users (The Brotherhood of Steel is a great target for theft if you want to stock up). However, if you're using your power armor all the time, you'll eat through them pretty quickly.*
Power armor is also highly detrimental to stealth. If you need to sneak somewhere, you may consider climbing out of your power armor first. Your power armor will stay where you left it, and your enemies won't find an empty suit of power armor the least bit suspicious.
As discussed above, you can't swim in power armor. There's a lot of water in the Commonwealth, especially on the eastern side of the map. Walking across the bottom of a body of water has its perks, but its easy to get trapped, its easy to drown, and it is very, very boring.
*A quick note. Power armor is still usable without a fusion core, albeit with certain restrictions. The armor moves slower, you can't use VATs, and, worst of all, it keeps beeping.
SPOILER: Power armor is great.
Where To Get Your Power Armor (No Spoilers)
Power armor is scattered all over the wasteland.
Some sets you can get through quests. The first set of power armor you get is through the Minuteman quest in Concord, and joining the Brotherhood of Steel will also get you a sweet set of free power armor.
You can also find power armor around the Commonwealth, usually behind computer terminals and locked doors. If you don't have lockpicking or hacking skills, consider bringing along a companion that does, such as Nick Valentine for hacking, or Cait for lockpicking. Without giving anything away, remember that Fallout games often have a certain logic to them. If you're stumped on where to start, think about where an unoccupied set of power armor is likely to be. (Hint: Before the war, only the military had access to power armor).
You can also purchase power armor frames at a few vendors, such as KLEO in Goodneighbor. They cost a few thousand caps (give or take, depending on your charisma), though, and considering the number of power armor sets you'll find in your travel, you don't necessarily need to buy them.