Note: This review will have some terms that deal directly with the Xbox 360 version (i.e. controls) but for the most part is exactly the same as other platforms.
The setting: 2277 in a heavily sealed vault underneath what's left of apocalyptic Washington D.C., aptly named "The Capital Wasteland". You are a Vault Dweller who's been living inside of Vault 101 your entire life with your father and few select other people, thinking that the rest of the world has been destroyed by the nuclear weapons launched at the end of World War 2 (Alternate Timeline FTW ^_^). One day, your dad mysteriously disappears and a close friend of yours tells you that he "left" the Vault. Your player is sent out into the Wasteland to find him and discover what he's up to. The following adventure is full of perils and triumphs and will leave you shocked at what happens next.
Fallout 3 was the best game I've played in a while. The game controls play like a first-person shooter (you can switch to 3rd person view by pressing the left bumper, if you wish to), with the left joystick to move around and strafe and the right joystick to look around your enviroment. The right trigger attacks with whatever weapon you have out and the left trigger helps you aim said weapon. The main difference between other shooters and this RPG is the help system named V.A.T.S. (Vault-Tec Assisted Targeting System). Anytime during battle, you press right bumper (not trigger mind you) and it sorta freezes time for you and shows you the hit percentages for individual body parts on individual enemies. Watch out though, you can't just infinitely riddle your enemies with bullets. Your character has "action points" (which increase depending on equipment and stats) that you use to do actions within VATS (You don't use action points outside of VATS and can shoot your enemies as much as you want when not using it) and if you run out during a battle, you can either go toe to toe with the enemies in real time or you can hide until your AP regenerates, which doesn't usually take that long. Depending on the weapon you have out at the time, each individual attack takes up a certain amount of AP. For example, sniper rifles, due to their immense power, take up at least a quarter of your AP per shot while The Wazer Wifle (A Laser Rifle that you can find and acquire within the game) can take more than 8 shots within VATS, but doesn't do as much damage as the sniper rifle. So if you aren't as good at aiming in a shooter game as some of the pros out there, this game gives you a second chance with Vats ^_^ Hooray!
While I'll try not to give many details away about the story, I have to tell you about choices you make across the game. While travelling throughout the Wasteland, your character (who is customizable in almost every aspect; name, race, hair color, skin hue, facial types, etc) will have to make decisions concerning places and other NPCs in the Capital Wasteland. While talking to other people, you have choices that you can make that would make them like, hate, or just be okay with you. It goes the same with any actions you take: Give somebody some respect, they'll respect you back; steal or kill somebody in a town, you'll never see them again and the entire town will hate you and probably attack you (Usually you can leave and come back in 3 days and everything will return to normal except for the deceased). All your actions have Karma (Good or Bad) and as you develop your Karma (It can be Good, Neutral or Bad. You cannot receive Neutral Karma through your actions, but you can have a neutral Karma level by doing both good and bad things) throughout your adventure, characters will have different reactions when you approach them. So be wary in making your decisions because they are irreversible...unless you decide to load from a previous save, of course.
Pretty much everything you find in the game is useful. Simple dinery sets and other misc. stuff can be used as selling items for bottlecaps (which is the currency in what's left of the world) or to make better weapons (like a steam gauge assembly, a fission battery and 2 other specific items can be combined to make a railway rifle) however you have to have the "schematics" to make said weapons. Although not every item can be used as a weapon like in Dead Rising, it's pretty close. Baseball bats, knives, guns, a chainsaw, and with the "Rock-it Launcher" anything can be used as a weapon from lawn gnomes to teddy bears. Or you can go mano y mano and just use your fists. Please note that even though you have the Vats system, you cannot hit enemies outside your range. If you use your fists, you HAVE to get up close and personal in order to do damage.
Just like other RPGs, you are able to choose new perks that would improve your character in and out of combat (i.e. Commando improves your characters hit percentages with two-handed weapons and Cyborg gives you more Damage Resistance and +10 to Energy Weapons) and there are also quest related perks that you would receive for completing said quests. Many of these perks go hand in hand and therefore you can make specific builds (a type of character that would excel at certain things i.e sniper, melee specialist, etc.). There are also skills that you can increase using points you gain at every level (dependant upon how high your intelligence is) and skill books you find throughout the Wasteland, and each of a max of 100. These skills help you get stronger and allow you to do things in and out of combat (i.e. Lockpick allows you to pick door and safe locks, Science allows you to hack terminals, Speech helps you convince NPCs to do certain things, Small guns increases the efficiency of your ability to use bullet weapons, etc). However, one of the main differences between RPGs and Fallout is that you cannot augment your starting stats very easily (Strength, agility, intelligence, endurance, perception, Charisma, Luck) after you have reached level 2. Certain quest rewards and bobbleheads (permenent increases) and chems/food (temporary increase) can help you with any stat changes but luckily for the player, there is a perk that helps you with any mistakes you may have made. Named Intense Training, it allows you to put one and only one point (at every level you choose the perk, up to 10 levels) into any of your stats. This is not without disadvantages however, because you only get to choose one perk per level and if you use it on Intense Training, you won't be able to choose any of the other awesome perks that are avalible to you, so it's up to you to decide what you want to do (Try to find out what stats you want by level 2 because that's the last time you can change the stats you receive at the beginning of the game).
Although this game is fun as hell, it's not without its issues. For example during VATS, you cannot cancel any attacks you make, so if an enemy decides to strafe behind a door or if your character turns and ends up aiming at a wall after you have decided to attack, you cannot cancel your attack and you waste your action points doing nothing to the enemy, even though in VATS you had a clear line of sight. On a rare occurance, some NPCs completely glitch out of the map only to reappear somewhere they're no supposed to be (I believe this may have been fixed by Bethesda Softworks with the title update). There are some quest glitches that would either hinder your progress or allow you to get repeat items, and a few others.
Otherwise from the glitches, which don't really show up that frequently anyways, Fallout 3 is the most awesomest (yes I know, not a word) game I have played in a while. And Bethesda is releasing more Downloadable Content to expand the game content (equipment, levels, story, etc) as we speak, so you'll be surely entertained for months and months.