looked through entire topic and was surprised.
some hardcoe modders will 100% add fallout shelter into Fallout 4.
simply come across and Incomplete and not yet numbered vault and start doing the same thing you do in shelter down to the deathclaw attacks..
only now you can deal with disasters yourself.
might seem like a boring idea, but i would be elated to be able to send dwellers into the wasteland where i might run into them, or even have them as a unique way to gather weapon/equipment.
it wouldn't be too hard beyond the coding for the timers and all that, all you need to do is what is in Shelter, have prebuild "rooms" that you can build from a menu on areas where existing doors dead end...
a big enough group tackles this you could even get voice acting for all those funny and cheesy lines that you get in Shelter..
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next up, simply a random "free gun" encounter at the start where you nearly get squished by a UFO and get a free alien blaster and like 10 rounds for it right after you exit the vault... just because starting off with the blaster is my favorite way to play the fallout series... might sound overpowered but it has actually happened at least 3 times for me where the firelance version spawned the moment i got to the supermarket in Fallout 3. only get like 10 rounds so while you can make any encounter really easy you can only do it in a heavily limited fashion as long as you are careful with how much ammo the encounter gives you.
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a VR simulation quest (or whatever allows you to explore the opening area) that has you go into your own memory of the day the bombs drop so you can explore that world (within the relative limits of how much of that version of the wasteland is actually rendered) and even replay the big boom if you feel like it. maybe even get to see your kid again or something crazy like im sure some movie has done. there have been so few chances to actually explore the pre-war world in the fallout universe that since we actually will have some prebuild objects in the game already, i would love to see a adventure either into the past or maybe a recreation of it (creative license freedom). Time travel is not really known as a factor in Fallout, but we do have plenty of VR stuff.
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here is a quest idea, you come across a singularly intact building in the wasteland. utterly pristine you have to explore it, but once inside you cannot escape and it turns out something is hunting you. a creature of the wasteland has evolved advanced psychic abilities and is using the knowledge inside you to trap you in a prison of your own making... creating illusions of various things from your mind such as your dead family, your hidden history (as you can tell it), and your life in the post war wasteland (do you regret killing those people? they regret it!) to confront a creature straight out of your nightmares and reclaim a piece of your past..
sound intresting? too straight forward? well here is the kicker. the choices you make will influcence your rewards, even your illusions are a result of your chocies and let you make your characters history your own... how would you react to being with your dead family? were you a doctor before the war? a soldier? imagine the ability to choose from many SPECIAL inspired pasts and recovering something related to it. Unique Gear and perks for each choice you make. say you confront the illusion of your dead family by killing your spouse and burning the house (they are already dead after all) or by having an emotional charisma check where you get a second chance to say your goodbyes before dispelling the illusion and moving to the next one. you get a perk related to those choices.. Were you a soldier? Obviously your old gun and gear will be found. i think this kind of a quest would be perfect for letting players make their own backstory for the sole survivor, letting them set in stone and gameplay a general version of their own ideal past. you can be pretty generic when playing the past vocation, after all the illusions will not be perfect.
also again this would be a chance to use those pre-war assets which i cannot stress enough will be big in this game.
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Dog Meat puppies... you find another dog and if you can get it back to one of your doghouses, then dogmeat will (off screen) have puppies and you can love their cuteness..
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i dont have to ask for car mods... there will always be a car mod...
i will however ask for flyable rockets... like the Delta IX rocket... and the ability to fly to the moon and collect decorative moon rocks you can sort of use as weapons. for instance... Bashing Rock(Melee) & Throwing Rock(ranged). because weaponized Moon Rocks are awesome. oh and if you can encounter lots of aliens and alien buildings on the mood making it like a second wasteland (requiring a spacesuit to travel admittedly) that would be cool... maybe have that as where mothership zeta was based at originally or something like that?