1. Change the way the Radio Station Works: Instead of summoning new Dwellers constantly, it has a random effect when harvested.
   A: It summons a dweller like normal.
   B: It summons a Legendary Dweller.
   C: It summons a Trade Caravan. You can then interact with this trade caravan to sell your excess resources for caps. I mean, Food, Clean Water (especially water), Stimpacks, and Radaway are all high demand commodities out in the wastes, and since you're most likely producing excess of all 4 of these anyway, it makes sense to sell these.
   
   adding onto that idea, perhaps you could also buy things from the traders as well: random weapons and clothing items at very high prices (like say 10-20x the cost). Perhaps even lunchboxes? That would be extremely expensive though, like say anywhere from 500-4000 caps per pop just to keep the buy boxes feature useful.
   D: A Goofy but useless scene will unfold outside the vault. These Include:
   
   - a bunch of feral ghouls will wander up to your vault, do the thriller dance, then leave.
   
   - Two Yao Guai will wander up to the vault door, High Five, then leave.
   
   - An alien ship will appear, beam down some aliens, who will knock on the door, then leave.
   
   - Two Super Raider factions will fight each other outside. The winner will then leave.
   
   - A nuke will blow up in the distance.
   
   - A bunch of Imperial Legionaries and Stormcloaks will show up, begin to fight, then stop and say "hey wait a minute... this isn't skyrim!!" Then get eatten by Alduin who leaves.
   
   - Fake Enclave invasion. A vertibird comes in, like it was about to drop off enclave soldiers, but then has a large bomb thrown at it and blows up. Liberty prime steps out, finishes off the rest, then leaves.
   
   - A several way battle between securitrons, NCR, and Legion.
   
   - You'll get a Fishystick. It does nothing.
   
   - (Insert more here)
   E: It summons raiders. Not everyone who picks up the signal will have the best of intentions. As an Addon idea: add the ability to salvage equipment and/or caps from raiders.
   F: It summons Super Raiders. See below for more info.
   G: It gives the option to summon a Legendary Raider. When this happens, a message will pop up saying "A malevolent voice answers your radio. Do you go quiet, or do you respond?" If you go quiet, nothing will happen, but it will delay the next encounter for 3x the normal amount of time. If you accept, it spawns a Legendary Raider boss fight.


2. Robots: These would be acquired either from lunchboxes or bought from traders or fought and salvaged in raids. Like legendary dwellers they come with higher than normal SPECIAL. Specifically, endurance and one other stat. Everything else is non-existent (All of them have one luck, for example. Protectrons have 1 charisma, 1 agility, 1 strength, 1 intelligence. Exception is Gutsy.) However, they cannot be trained, cannot wear uniforms, and cannot be given weapons (They come with them however.) Also they cannot breed with dwellers (obviously). Also, robots consume power instead of food and water, and have no happiness. If your power bar is in the red, they shut down. They can be "packed up" and sold if not wanted. They come in several flavors:
   
   
   
   
   

   Eyebot (Common): High Charisma (even though this doesn't mean anything), Very low endurance. Can explore, but doesn't gather materials. Instead it acts like an explore-and-forget version of the Radio station, though much slower than even a 3x1 staffed by a single char1 dweller. If assigned to a room other than the radio station it won't contribute anything but will make the dwellers in it happier.

   
   

   Protectron(common): High Perception, low endurance. Cannot explore (too slow). Cannot put out fires. Comes with a laser pistol equivalent.

   
   

   Cyberdog (uncommon): Basically just acts like a robot version of a pet dog, but stronger.

   
   

   Handy (common): High Agility, low endurance. Can Explore, can put out fires. Comes with a halved flamethrower. Can own a pet (but can't acquire any of its own).

   
   

   Robobrain(uncommon): High Intelligence, moderate endurance. Can put out fires. Can explore. Uses a mesmetron attack which does no damage but randomly causes raiders and radroaches to attack each other.

   
   

   Roboscorpion(uncommon): (Honestly I don't know.) Can explore. Comes with a blue version of the laser rifle that does more damage.

   
   

   Gutsy(Uncommon): 5 in all stats. Cannot put out fires. Can Explore. Uses a Plasma Pistol.

   
   

   Sentry Bot (rare): High Endurance, 1s in all other stats. Moves VERY fast. Cannot Explore (no hands). Can put out fires (missle launcher replaced with fire extinguisher). Comes with a Minigun. Will not contribute to production if assigned to a room.

   
   

   Securitron MK I (rare): High Strength, Moderate-high endurance. Can put out fires. Can Explore. Comes with a 9mm machine gun.

   
   

   Hover Robot (Tactics) (Uncommon): Very Low Endurance. Cannot contribute to production. Comes with a Missile Launcher.

   
   

   Humanoid Robot (tactics) (Rare): Basically a robotic Dweller that follows all the rules of a normal dweller. Can be equipped with armor, can be given a weapon, can have a pet, etc. However, it does not count towards your vault limit, and it runs off of power like all other robots.

   
   

   Securitron MK 2 (Very Rare): Max Strength, Max Endurance. Can Put out Fires. Can Explore. Comes with a 2x Missile Launcher.

   
   

   Think Tank (Very Rare): Max Intelligence, Low Endurance. Cannot Put out Fires. Cannot Explore. Comes with the same weapon as the Roboscorpion.
   
   
   Legendary Robots: These can only be gotten through lunchboxes.
   

   ED-E: 3 ST, 10 PE, 5 EN, 1 CH, 1 IN, 10 AG, 5 LK. Can be assigned to tasks, and can be assigned as a pet but otherwise acts like a normal eyebot.

   
   

   Sgt RL-3: 5 ST, 7PE, 7 EN, 4 CH, 6 IN, 5AG, 5 LK. Can act like a pet. Comes with an enhanced plasma pistol. Can explore. Can put out fires.

   
   

   Yes Man: 7 Charisma, 7 Endurance, 7 Luck. Comes with a Gatling laser.

   
   

   Rex: 6 ST, 8 PE, 8 EN, 1 CH, 1 IN, 8 AG, 5 LK. Acts like a pet.

   
   

   K9: 6 ST, 9 PE, 8 EN, 3 CH, 6 IN, 8 AG, 7 LK. Acts like a pet.
   
   Skynet: 8 ST, 7 PE, 6 EN, 1 CH, 10 IN, 7 AG, 5 LK. Can be equipped with weapons. Can put out fires. Can explore.

   
   

   
   
   
   


3. Super/Legendary Raiders: Basically an inversal of Legendary Dwellers, and a sort of "Boss Fight" if you will. These raiders are of a different faction than normal raiders, and can be either Enclave, Outcasts, Robots, Talon Company, Super Mutants, or Legion. They're a lot stronger than normal raiders (Except legion, who are simply more numerous and come in a squad of 9 rather than the usual 3.) But in conjunction with the idea of raiders dropping loot they offer better rewards for beating them. Better armors, weapons, or in robot's case, the chance to salvage robots.
   
   Every now and then though you'll instead get "Legendary Raiders". Which really are the oppose of Legendary Dwellers. These are singular enemies that are extremely strong and will take A LOT of power to take down. They carry a legendary weapon and have INSANE health. These only occur through the Radio Station encounter, and even then, only through choice.
   
   Candidates include
   
   - Caesar (with Praetorian Guard)
   
   - Legate Lanius
   
   - Sgt. Dornan
   
   - Lou (the supermutant boss from fallout 1)
   
   - Colonel Autumn
   
   - Frank Horrigan
   
   - Father Elijah
   
   - Dr. Mobius
   
   - The Think Tank (All of them)
   
   - Ulysses
   
   - General Jingwei
   
   - Eulogy Jones
   
   - Commander Jabsco
   
   - Motor Runner
   
   - Ashur
   
   - Salt-Upon-Wounds
   
   - Vulpes Inculta
   
   - Tabitha
   
   - Gammorian
   
   (more to follow)
   
   Beating a Legendary Raider will net you:
   
   - Caps equal to his health. (total health if they come with a possie)
   
   - Lunchboxes (number equal to his/thier health/1000. But you're guaranteed to get at least one.)
   
   - A legendary Armor and Weapon


4. Pets: Every now and then an explorer may return home with a pet. This can be a dog (most common), a Mole Rat, a Radroach, a Gecko, a Nightstalker, a Cazador, a radscorpion, a Duraframe Eyebot (which has similar stats to a regular eyebot but does not behave the same way) a roboscorpion (yes I put them down as pets. Not sure how to implement them as robots), a wanamingo, or in VERY rare instances, a yao guai or deathclaw. They'll have their own SPECIAL, which compounds onto the dweller's own stats by half rounded down (like a sort of "second armor". If the dog has 6 Perception, the Dweller gains 3, etc.). The odds of finding one and of what kind are determined by Charisma (making it actually useful for a change). It also increases their happiness a bit, but they do eat food and water (power in the case of roboscorpions, cyberdogs, and duraframe eyebots) like any other dweller even though they don't count towards the dweller limit. You could also give pets to other dwellers. Pets will follow dwellers around and fight off intruders along with them. They'll run away from fires though. Just like dwellers they can die, so watch out.


5. Robots cannot acquire pets, and cannot have them.


6. More weapons, clothing, and Legendary Dwellers from previous games. Specifically stuff from Fallouts 1, 2, and Tactics. But also new vegas (I know there is some armors from them but that's about all I've seen of them).

Also,