Wanted to post but BROWNSER AT MY POST SO LET"S GO AT IT AGAIN
My thoughts on how it would work, mechanics-wise:
Geoscape: Smaller scale, more detail than X-COM's, focused on Southern USA - thinking Gulf South minus Texas, mostly states near Florida. Dunno how to do without oddities in Earth's globe or the day/night circle.
Instead of the Founding Nations, it would be something like a lot of city-states, tribal confederations, chiefdoms, republics, kingddoms, townships, weirdo sects, etc, helping the Brotherhood of Steel in exchange for protection against raiders, mutants, marauding tribes, crazy cults, pirates and the Plants (which I have come to call "The Bloom" or "The Blooming").
cont because I have to leave.
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Because your movement is far slower and the region bigger in detail, time is more important, as well as location.
Expanding on my idea, my idea is that in the early-game, the guys who stabilish your base/your first soldiers are pretty much a bunch of brotherhood initiates with some basic training, pretty much a bunch of jumped-up tribals. The whole start is pretty much a scouting/combat exercise - The Midwestern BOS doesn't consider the whole thing anything more than that, most elders think all the weird rumours from out of the midwest are ridiculous, but might as well investigate anyway.
So, early game your guys are pretty much a bunch of jumped-up tribal noobs sent to scout the area, find out what's up in the region, find pre-war sites of interest (of which your starting base is the first, as classic BOS tradition of taking over pre-war bunkers. No need for upper-level bases!), make links with the locals, the works. Low-key stuff.
Think Solarius' X-COM Files - the early game is about finding the real threat (I mean, plants ravaging human civilization and regenerating the wastes? That's ridiculous, right?), and once you do the main MWBOS starts supporting you. So yeah, no Paladins in Power Armor this early. Or FOT, where your dudes are tribals straight out of training using some crappy firearms, probably stuff the Brotherhood took off some dead raiders a paladin killed with his powered armored pinky on a dare.
Vehicles/Interception: Would love to have Land, Water (river AND sea!) and Air vehicles.
My thought is that at first your "vehicles" are pretty much local guides - AKA a bunch of dudes who lead you around and stuff. No weapons (maybe later give them a anti-vehicle weapon or something?). Then you get other vehicles - say, a two-seater bicycle (land, fast, no weapon, two persons only), a brahmin carriage, a canoe. Maybe better guides.
Then better vehicles - bigger boats, vehicles using biofuels (fresh from sugar cane slave-labour plantations, of course). The end vehicles would be classic Fallout battery and fusion-powered cars, trucks, etc - So Fusion Cells are pretty much the equivalent of Elerium - they even power the energy weaponry!
Air vehicles would probably show toward end-game - maybe starting with a basic air baloon and then zeppelins, maybe a propeller plane. I think the "Ultimate Craft" would be something aerial, quite cool - no, NOT a Vertibird because I think they're already over-used in Fallout - maybe a huge-ass Zep or chopper.
The enemies progress in the same way so early on you see pretty much parties of raiders going around, and later enemies would get their Mad Max on so you have to put a gun in your buggy and such. No idea how the plants would even do it, maybe their "vehicles" are actually animals they piggyback on, so you have to send a plane to shoot off a lot of infected birds or something like that. Weird, right.
Tech and gear: Game starts on low-tech, tribal/scav level - crap guns, crossbows, spears, molotovs, boom bugs, knives, etc. You can get more gear to buy through "research" like making nice with merchant guilds and such, and to manufracture by finding blueprints, which range from "how-to" home-made stuff guides to pre-war blueprints. Eventually once you get your superiors onside for The Real War, you can buy stuff directly from the Brotherhood, like Laser Rifles. But that sorta thing is EXPENSIVE, because its a long and the Brotherhood doesn't take chances when it comes to protecting their tech. You can even buy good soldiers, but more on that later. Not sure if Power Armor should even be buy-able (or manufactured), or just immensely expensive.
Also this means that explosive spam isn't a doable strategy for a certain part of the game. Only by mid-game you start getting good explosives.
Wacky idea: You actually take a penalty for destroying equipment in missions - so something like a pipe rifle out of scrap is insignificant, point-wise, but blowing a unique pre-war prototype or a dead body in Power Armor? Hahahahahahahahha enjoy your minus points.
Economy: A lot more rough-shod than the usual X-COM game. A lot more scavenging and jury-rigging. Would love to have something like a X-COM Apoc-style market.
Battlescape: Your soldiers are more "sturdy" than the average X-COM rookie, not because they're tougher (they're humans... well, most of them will be), but because the weapons simply have lower power. Would also need some way to feedback hits that damage the target.
Also, I want a more RPGish experience. Think Fallout Tactics transplanted into X-COM. Maybe even add different new stats and such to represent some of the classic Fallout mechanics - say, split Firing Accuracy into Small Gun Accuracy, Big Gun Accuracy, Energy Accuracy, etc. X-COM already has Throwing and Melee Accuracy.
One problem I have is how to depict Fallout-style critical hits and aimed shots. Maybe add a new stat (Critical Chance? Luck? Precision Aiming?) that deals with the X-COM damage rolls? The idea is to differentiate between a soldier who just shoots center-of-mass very well and someone able to shoot weakpoints and such - the classic Fallout Sniper vs Fast Shooter dicotomy - go for the eyes or just send a rain of lead? Maybe involve attack types too.
Soldier Ranks: I'm thinking:
Rookie/Initiate
Squaddie/Squire
Sergeant/Junior Knight
Captain/Knight
Colonel/Paladin
Commander/Head Paladin
(personally I would love to pad it out to properly display the Brotherhood ranks, but I would settle with making promotions far slower than base X-COM. So yeah it will take a while for your scrubs to become Paladins).
Early on your first soldiers are your starting eight brotherhood, and native locals with low stats (because they're untrained, undisciplined, etc). Your starters are a bit better than them. Later on you can recruit BOS initiates (trained, unlike the locals, but more expensive) higher-ranking soldiers, with a cost. Maybe even recruit Knights.
There would also be other soldier-types - Like Mercenaries. Maybe even mutants - say, Ghouls, Super Mutants, maybe something like a Swampfolk or Trog - as auxilia but they lower your squad morale. Super Mutants would probably be the strongest, but most expensive type.
One idea I had is that you can eventually enhance your troops with expensive, but totally-worth it implants, like in the original Fallout games.
One problem I had was Psionics - Psykers exist in Fallout but they're rare. Outside of Beastlords and maybe the rare mutant psyker the only foes with psionics I thought of were the plants. And no psionics for the player at all. Alternatively, you can eventually use psionics because the Bloom is also a psionic entity (think SMAC Planetmind, but plants instead of fungus), so you can sorta "hijack" that energy and use it, but once its destroyed the psionics go away.
Opponents and missions: Early on your opponents are dangerous animals and stuff like raiders, tribal marauders and general waste scum. As the game goes on you start to fight well-armed foes and mutants and other organized groups as well as The Bloom.
There's also the idea of having Piratez-style oponents you can't attack without losing points, but there's worthwhile loot over there - say, traders, governments' troops, non-inimical factions, etc.
The UFO equivalents ("Unknown Travelers?") do missions depending on their make-up - so raiders raid, terrorize and kidnap, traders trade, plants grown and attack humans to use them as fertilizer or clean out a threat, technocratic orgs go after pre-war tech, etc.
Oh yeah, one idea I had was the idea of missions to Pre-War facilities and ruins for scavenging. I'm thinking there would be two kinds:
1. Scout Pre-War Cities, which would be always available once per month in all the local pre-war cities. But on the other hand, the local loot is pretty much random so most of the time you just fight some scavs or animals and get crap. But sometimes you come across something good.
2. Pre-War Facilities - found either by patrolling/"radar" (VERY HARD), or by "researching" maps found sometimes in possession of certain enemies. These would be harder, with the player fighting other scavs (and even other technocratic factions), dangerous mutants or security robots. Maybe even some timed missions to represent high-rad areas.
