These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
There is not generally much overlap between fans of the first two game and fans of the third one (though exceptions exist), and the disagreements between the two groups can get rather...vehement. It even spills over to TV Tropes - much of this page's edit history can be summed up as a permanent low-intensity Edit War between Fallout 1 and 2 fans and Fallout 3 fans.
There is even a splinter group of Fallout 1 fans that dislikes Fallout 2 because they felt it introduced "too many silly elements."
Saying anything negative about any game in the series with the exception of Brotherhood of Steel will usually get you yelled at, and called either a 'stupid Bethesda fanboy' if you complained about the first two games or Tactics, or a 'stupid NMA troll' if you complained about the third one.
Notably, the biggest mistake you can make is complain about the graphics in the first two games. Que a lecture on the character models being actual clay models.
Obsidian decided to go above and beyond in New Vegas. Not only is there no dart gun, which was effective against deathclaws in Fallout 3, but they now come in packs and have titanic damage thresholds, meaning most (as in, everything smaller than the anti-materiel rifle) will only do Scratch Damage. Thankfully, they now can't spawn randomly. You'll know where they are.
Yao Guai are the not-quite-Demonic cousin of Deathclaws. They're easier to kill and do less damage, but unless you're high level they are still dangerous, especially in packs.
Broken Steel adds in Super Mutant Overlords. You won't encounter them until you're a pretty high level, but they're equipped with powerful weapons and are ridiculously tough. To make matters worse, they have an unblockable damage bonus of around 20-40 HP per shot depending on the weapon. Even wearing power armor and toting a rocket launcher, your ass may well be handed to you.
Overlords are nothing compared to the Albino Radscorpions, which have almost as much HP as a Super Mutant Behemoth! Their only saving grace is their lack of a long-range attack, so you can get out of dodge by climbing on top of something they can't reach you from. That said, considering their durability and damage potential, running the hell away is a good idea too.
And rounding out the Broken Steel trio are the Feral Ghoul Reavers. Oh hey, they look just like Feral Ghoul Roamers, piece of ca- WAIT WHAT.
Damn those swampfolk/tribals and that magical unresistable damage bonus!
Any player trying to do "Those!" at any level below ten or so will find the fire-breathing ants a hell of a challenge. Sometimes it's an easier and smarter idea to just kill one ant on the street and just do the quest later in the game, so that their levels stay somewhat low while you have a wider arsenal to gun them down with. Or just stand on the ledge outside of town and snipe them.
The Enclave Soldiers in Fallout 2 were the bane of players everywhere. They are pretty much immune to electric damage and heavily resistant to nearly every other kind of damage due to their power armor, not to mention they have extremely high health and can effortlessly kill you in one turn even without a critical hit. Because of them, going anywhere near the coast until you've reached near endgame levels was instant death. Unlike most Demonic Spiders however, it's pretty easy to tell where they are and which places to avoid (anywhere near the coast pretty much).
Those stealth suited aliens. Hell, you feel pretty stupid by shooting a mini nuke to a 3 foot tall guy and watching he shoot back at you with his alien rifle just after.
Any kind of robotic enemy will be a huge pain in the ass as well. Did you remember to invest some skill points in energy weapons, despite usually never coming across one until at least the halfway point? You better, because energy weapons and explosives are the only way deal reliable amounts of damage.
You can't kill children in Fallout 3, but enslaving them is A-OK. Taking a strong moral stand, there.
Also, in the Pitt, an expansion to Fallout 3, you are assigned to kidnap Ashur's baby girl, who has immunity to the radiation disease affecting the rest of the Pitt dwellers. Wernher and his allies hope that by doing so, they can both get the treatment, then ransom off the child. But since you have to pretty much ice every raider there to kidnap the kid, who's going to pay a ransom? Wernher should win automatically, since everyone under Ashur's command is dead.
Also, and here's a big one. They all have seem to have forgotten how to filter water. You run the water through alternating layers of sand and charcoal then boil it. This removes all toxins, bacteria, and harmful particles such as radioactive fallout. This may make Project Purity a moot point. Guess they don't have any copies of the Scout Handbook on the East Coast.
They may not. The Scout Handbook in Fallout 1 doesn't exist in Fallout 3, and the skill books may or may not be Story And Gameplay Segregation anyway. Other intact "pre-War books" are insanely valuable, if you sell them to some of the few people who seem to realize their importance, and pretty darned hard to find.
Well, at least in New Vegas, that is addressed, with a good survival skill, your character understands how to make instant potable water using a couple pitchers and some surgical tubing.
Although, considering that there are actually quite a few bottles of Purified Water laying around the Capital Wasteland, it's likely that there are some people around who do know how to do it. Not to mention, the purpose of Project Purity is to purify the entire Potomac River and bring clean water to everybody, and you need big machines to do that.
The Lockpick Bobblehead in 3 is the only bobblehead that doesn't bobble. Possibly because someone used the spring to pick a lock.
Isn't the world of Fallout set in the 50s vision of the future? Then what's with all the stuff that's different!? Society, language, culture in general.. It keeps getting less and less like the future of the 50s! Wait a second.. Does this mean the only thing that could pull Fallout America out of the 50s mindset was all out nuclear war?!
Watch the intro and listen to the charming Ink Spots tune "Maybe". Then play the game. Now listen again. Maybe the one who is waiting for you will prove untrue. Then what will you do?
I Am Not Shazam: The Vault Boy is NOT called PipBoy. Even the developers of Fallout Tactics fell into that. Vault Boy is the blond, wavy haired man in the blue jumpsuit, and PipBoy is the redhead pixie in the yellow and orange spacesuit, in case you were wondering.
And his name is notFall Out Boy either, despite his face being prominent in all Fallout games.
The Sniper perk in the first two games. With high luck, almost every hit will be a critical hit. Combine with shots to the eye and a decently powerful weapon and only the strongest enemies will survive more than one round of combat.
Jinxed with Luck 10. Your obscene luck (usually) counteracts the negative effects of the perk, but your enemies will constantly be hitting themselves, each other and breaking their guns and limbs on a regular basis. Although this means that the rest of your party become a lot less helpful and much more dangerous to you.
Some of the special encounters that you come across in the Wasteland in 1 and 2. The crashed Nuka-Cola truck which gives you over 10,000 caps at a high enough Luck level, the Alien Blaster, the Solar Scorcher, the Red Ryder LE BB Gun, the Holy Hand Grenade, the Monument Head and the Star Trek Hypos.
Mothership Zeta DLC. After finishing, you end up with a huge amount of super healing stuff, overpowered weapons and ammo for those weapons. Good bye scavenging and weapon maintenance, hello Alien Desintegrator!
Finishing Operation: Anchorage will unlock a chamber filled to the brim with awesome weaponry, plus two game breaking suits of armor. The Chinese Stealth Suit always gives you 100% stealth (and allows you through a glitch to wear all the clothing you have in your inventory at once, giving multiple armor and stat boosts at once), and the Winterized Power Armor, which never degrades and allows you to circumvent the usual restrictions to wearing Power Armor before completing the required story mission.
With Broken Steel installed, Three Dog will talk about the Enclave's defeat at Jefferson Memorialeven if you haven't gotten that far in-story.
In the Mac port of Fallout 1, the aftermath of the slaughter of the ghouls at Necropolis will sometimes leave the dead bodies standing upright, as if they're mindless flesh statues, frozen at the point of their death. Which is very creepy when you're wandering around looting them.
Similarly, in New Vegas, there's a room in Gommorah with a dead hooker in it that you visit for a quest. Sometimes when you enter she'll be standing and acting as a life NPC, even trying to seduce you, while you examine her for rigor mortis.
Hilarious in Hindsight: A character in combat armor outside the Boneyard (Fallout 1) wears a pin reading "I'm Chris and you're not". Chris Avellone joined production for Fallout 2, and has become the name most associated with the franchise.
The Woobie: Harold in the three main games. He has lost just about everything he had by the time you see him in the first game, and suffers a Fate Worse than Death in the third. At least you can actually do something about his situation in that case (or don't, if you choose to restrict his growth instead of mercy-killing him or expanding his fertility. Thanks, jerk.).
Take That: At those who idealize the past, and wish they born in a time than the period they live in now. Applies to the 50's in particular.