This game does not require the amount of skill used in other games, such as Dead Space or the Uncharted series, where you are constantly running, jumping, dodging bullets while keeping an eye on your ammo and health level during a playthrough on hard or crushing modes. In fact, the game tends to become easier as your character levels-up, your weapons grow stronger, and you've mastered using the V.A.T.S. mode.

What this game does require, however, is a fair amount of time. Though not nearly as many hours will be spent as compared to Dragon Age: Origins, in Fallout 3 you can obtain the platinum in one, long playthrough. A hundred percent of these trophies are certainly doable, provided you have a lot of free time on your hands.

Specifically, often make new saves!! Do not overwrite the same single save over and over, because there will be times when you've made a mistake, and need to go back. Once, I accidentally met a character I wasn't supposed to meet yet, which jumped the main story forward - I received the next trophy for completing the umped mission, but missed the one before.

Keeping a number of saves will also help you when encountering glitches. A popular one is during Kicking Up the Trail, in which you're escorting Dr. Li. At the Citadel, she is supposed to use the intercom to allow you inside, but some people have reported that she just stands there, doing nothing. In this case, reload a past save, shoot your way out of the sewers again, and the glitch should be rectified.

The majority of the trophies are story-based, which include side-quests. Once found, they are easy to do even without a walkthrough (though we provided several in the Links page). After a mission has been selected, simply follow the arrow on your compass to where you need to go.

Slayer of Beats, which requires you to kill 300 creatures, is easily done during the course of the game. But Doesn't Play Well With Others is a bit more challenging, since you won't encounter 300 people simply by going through the story. Our advice: go out of your way to kill people, particularly later on when your character grows strong. If you're near the end of the game and still have not acquired this trophy, then head to areas and campsites where you remember seeing thieves and bandits, and wipe them out.

For Psychotic Prankster, in which you have to slip a grenade or mine into someone's pocket, we recommend either having a high stealth skill, or use a Stealth Boy. You must be in a sneaking position to pull this off. Also, make sure you've saved just before performing this prank, for you will lose karma. Once the trophy is acquired, reload, and continue with the game.

For Weaponsmith, we recommend that once you have a home (most likely in Megaton) you'll now have access to several lockers, in which you can store an infinite amount of stuff. Reserve one of these lockers for only equipment necessary in making custom weapons. Then, using the list provided in our Links page, keep an eye out for these items as you play. Once you have them all, and the necessary schematics, simply build one of each, and the trophy is yours!

Same goes for The Nuka-Cola Challenge. If you come across any bottles of brightly glowing blue Nuka-Cola, DO NOT DRINK OR SELL THEM! Instead, toss them in a locker. You'll need to collect 30 in order to acquire the trophy.

For Data Miner and Keys Are For Cowards, make sure you have every computer you come across, and pick every lock you find. Overall, there should be plenty of locks to work out, but the computers are a bit more rare, so keep your eyes peeled. Also, you may come across a safe which can either be picked or its computer hacked. In this case, pick the lock first, then even though it's open, hack the computer anyway. Since you only have 4 tries to hack before the computer shuts you out, save the game just before trying - this way, you'll have four chances to score the password instead of three.

You may notice there are trophies for reaching levels 8, 14 and 20, with each for the three karmas. Does this mean you have to play the game three times? Hell, no! Here's the trick: Once you get the trophy for reaching one of these levels, save the game, then load up a past game. Head into Megaton, duck into the hospital, shop and/or church, kill people inside (make sure they don't escape and sound the alarm) and start stealing things. Continue doing this until your karma is down to Neutral, then head out of Megaton and start killing random enemies until you get the trophy. After that, load up the same game, and repeat until your karma is down to bad. This works, of course, if you maintain Good karma. It's always easier to become bad than it is to become good (in life, and Fallout 3).

On a final note, make sure you've acquired every other trophy before embarking on the final battle. Once you beat the game, there's no going back.

Since most of the trophies are story-based, here is a Walkthrough by IGN, which includes all Side Quests and DLC:
http://guides.ign.com/guides/901269/page_3.html

And if you don't find what you're looking for there, try this Walkthrough by Wikia: http://fallout.wikia.com/wiki/Fallout_3_walkthrough

Mahalo also has a rather detailed Walkthrough, though is text-based and lacks pictures:
http://www.mahalo.com/fallout-3-walkthrough

Here is a Map of the area, useful for the One-Man Scouting Party trophy:
http://fallout.wikia.com/wiki/Fallout_3_map

And just in case, here's another Map:
http://fallout3tips.blogspot.com/2008/11/most-complete-fallout-3-map.html

Here is a forum which lists the parts needed for making Custom Weapons. Keep scrolling down, and you'll learn the location of the schematics, as well:
http://www.achieve360points.com/forums/showthread.php?t=99189

This is a list of the locations for the Nuka-Cola Quantum bottles, necessary for The Nuka-Cola Challenge trophy. (Tip - give the bottles to Sierra rather than Ronalds, because Ronald is a jerk!)
http://fallout.wikia.com/wiki/Nuka_Cola_Quantum

Here is a list of the Bobblehead Locations:
http://planetfallout.gamespy.com/wiki/Fallout_3_Bobblehead

As an added bonus, this is a useful Youtube video which demonstrates the Psychotic Prankster trophy, provided by andrews1022:
http://www.youtube.com/watch?v=f22uYOJ4_50

Finally, here's a basic Trophy List:
http://www.ps3trophies.org/game/fallout-3/trophies/