(This blog assumes you've arrived from another place and you've been toying with the system and setting for Fallout 2D20. Get it here if you haven't , continue on otherwise)
Fallout 2D20 is about exploration in the most granular sense. If you're familiar with the Fallout games, the common approach to scavenging for survival is to take anything that is and isn't nailed down, and then to take the nails for good measure. Junk is practically the unofficial sub-currency for Fallout 4, for example, and in most cases you'll run into choice fatigue when your weight limit starts to cap out — since virtually everything in Fallout 4 has some worth to it's encumbrance cost. With a player-use or GM-use map of a settlement, you'll want to cultivate the same relationship between the player and the environment, providing a goldilocks "sweet spot" of content density and opportunity. Here are my tips:
Limit population to 1/10th the original population pre-war: the caveats here pop enough holes to deflate the case, but the rule of thumb should help give you a visual idea of the damage and destruction having made whatever city you're occupying less dense. Apartments may be flattened rock piles, sufficient to shelter but not to house any significant number of people. There's plenty of speculation about Fallout and overpopulation, but generally if you're building a town, try to imagine a population limit of 1/10th it's original numbers and see if that doesn't feel right
Implement something underground and unexplored:
Your plot can quite literally deliver itself to places you need. Make a sewer, a cave, a tunnel, or a basement network. The big "you don't know where all this goes" element allows the storyteller to allow for it to help NPCs escape, players arrive where they need, and any twist and turn you need want. Mole rat tunnels and dilapidated vaults here here as well.
Bridge the gap between raiders, bandits, and settlers:
This is probably not far from the "evil races" discussion in TTRPGs, but you're not GMing a Bethesda game, you can muddy the waters and make the lines blurrier. I had a settler in my town with an uncanny knack for building scrap metal fortifications and spikes — something our wanderers immediately associated with raiders — but otherwise the named NPC was timid and calm enough that nobody saw the need to confront him on the matter, accepting that his story isn't one the players had the need to frame into an extreme of "friend or enemy". We're playing a game about people surviving the end of the world, and after accounting for lines and veils and the rules that the PCs follow, it should feel quite clear that the difference being a settler and a highwayman is hard to quantify if both are doing whatever it takes to feed their own.
Food, water, waste, and scrap:
Things accumulate. Waste, rain, trash, campfire ashes, mole rat corpses, etc. Ask yourself where the excess piles up and how the passage of time is measured. You can tell how old a craftsman's shop is if they aren't clean enough; dust, old tools, outdated calendars, and paperwork builds up as things fall out of priority. In Fallout, it's quite likely that *everything* should feel like that. There's no pressing need to clean up after oneself, and no post-apocalyptic EPA to tell you that burning used tires in the middle of an old golf course is a bad idea. Let your settlement age, visualize the time lapse are quarries become lakes, fields becomes forests, and houses collapse into husks for termites and wildlife.
I'll be back next week for a breakdown on the locations named in the map, but enjoy Lex Vegas in it's glory.
I used icons from the Wiki (https://fallout-archive.fandom.com/wiki/Category:Fallout_4_location_icons) and a sourced Google Maps conversion (https://snazzymaps.com/style/87718/fallout-pip-boy)