There are a couple great guides on how to play the game, but nothing specifically for Scenarios, so I thought I'd make one as I'm going through them. Generally speaking you can treat Scenarios like Forum Requests, i.e., build a stable town and do them on the side, especially the easier ones. Some, however, work better if you simply ignore everything else and sprint towards the goal. If the town collapses after you're done, well, that sounds like a them problem.

Most Scenarios also allow you to change the difficulty and map settings, which I highly recommend you take advantage of to make your game as easy as possible. The exceptions are Bleak Times (aka un♥♥♥♥ this settlement) and Hunters and Hunted (aka survive raider attacks). Some will let you change most settings but lock certain options, for example The Long Summer (aka survive droughts) which won't let you change how often it rains, or The Bet (aka find seeds) which won't let you just... give yourself all the seeds. Obviously. This guide will assume that you have set everything on the easiest level you can, because that's what I did. I'm also going to assume you can set up a successful colony on your own and will do that as a baseline strategy.

A further note: the Scenarios are not arranged in order of difficulty, or... any order as far as I can tell. I tried to alternate easy and hard Scenarios so I wouldn't get bored, but you can do them any way you like, or in parallel if that's your jam. This guide is in the same order the game shows them for ease of reference.

• Own 6 seeds

• Own 8 seeds

• Own 10 seeds

Despite the framing in the flavor text, this scenario is not timed and you cannot actually lose the titular bet. This is basically just a normal game that ends when you collect enough seeds. Both Field and Orchard seeds count, and you don't need to plant them, just own them. Your priorities here are the Trading Post and, optionally, the Expedition Station.

The Trading Post is a more reliable source of seeds, but also more expensive. Once you have the building, you will need to get each trader (or at the very least Rusty and Sorenson, as they are the most likely to offer seeds IMX) to like you. This can be easily accomplished by simply giving them one of whatever you happen to have the most of the first time they show up. After that, you will only need to meet the bare-minimum requirement for "fair". I suggest overstocking Decontamination Kits, as these are some of the highest-value items and fairly easy to make.

The Expedition Station requires more investment, but any seeds you find are free (minus the cost of the expedition, natch). In particular, these locations are guaranteed to give seeds, provided the expedition succeeds at the relevant task:

• Combine Harvester
  
  • Look for the green one, not the white ones.
    
  • Only explore the cockpit. There's nothing in the container and your settler will hurt themself. You'll only need one action point total and there's nothing to bring back, so don't bother to send more than one person. This is the most useful of the bunch as it will always give you a seed you don't have.
• Greenhouse
  
  • There are five different greenhouse Ruins, but only four of them have seeds. The one that doesn't is also the one that doesn't require a Farmer badge.
• Bar
  
  • You don't actually need to send a Pubkeeper. When you check the counter one of your expedition team will magically become proficient in bartending and you can promptly use them to pass the Pubkeeper badge check.
    
  • The seed itself comes from the drunk guy passed out upstairs. It's always a wheat seed, and it will start a quest to plant wheat and brew beer. There are no consequences for failing or declining this.

• Survive to season 40 (starting from season 26)

• Store 10k Water and 5k Food
  
• House and clothe all settlers
  
• Upgrade Bus Wreck to Mounted Bus
  
• Build one each: Medical Facility, Rainwater Collector, and Irrigation Plant

• Build one each: Scrap Catcher, Electric Water Pump, and Hemp Weaving Mill

You are given an already established settlement that you must rescue from their own incompetence. The stated problem is that a big sandstorm came through and broke everything. The actual problem is that this settlement was laid out by a moron. You will always have the same map with the same settings, population, weather, etc, etc. There is a lake to the north, a tiny mountain and cemetery to the west, a forest to the south, and some housing in a valley to the southeastish. The town center is the bus and a few fields, and a bunch of open space, presumably for future development. This sounds nice in theory, but in practice all of these things are eighty million miles apart, so settlers waste most of their time walking back and forth. Let's fix that.

IMMEDIATELY pause time and do the following:

• make sure your builders prioritize building, then roads, then repairing
  
• set all broken Cabins, the Food and Water Points, all three Wells, and the decorations to be demolished (leave intact cabins for now, we'll replace them as we go)
  
• set the existing Shelter to "Old and Infertile" - we will demolish this later but for now we need to pump out future workers and that means only fertile adults and kids in cabins
  
• (optionally restart time here for a bit to get your old buildings out of the way and free up some space)
  
• order 8-12 new Cabins built by the fields near the center of town, and ideally a new Shelter if you can squeeze it in. You will probably end up with empty Cabins, but that's fine, these settlers are smarter than Banished's and they'll pair up by default
  
• build 1-2 Storehouse(s) by the lake/fields (or build one and pause one). There are two slots between roads exactly the right size for this. You don't have to use them, but you may as well
  
• build a Well and a Rainwater Catcher on the road opposite the Water Tower, optionally add some more Water Towers in planning mode to be built later
  
• drop your number of Morticians from 5 to 1, make them builders instead. Max out your food and water gatherers; you'll adjust this later as your game progresses, but for now this is the thing that will kill you fastest. Leave the farmers alone, you only need one per field anyway. Play around with the ratios of workers per job site, and remember you are going to be shorthanded for a hot second while the kids grow up
  
• click "Repair Next" on the Fishing Hut; when this is done, force-repair the Charcoal Kiln
  
• go through your Forester's Lodges, Gathering Huts, Herbalists, Scrapyards, etc and change their fields of work to something useful; they are all set to the default radius around the building. I scooted my forest up a bit to sit in the natural curve formed by those two lakes, and my Scrapyard I set to clean up the town/forest and then on the trainyard ruin to the west-ish.
  
• drop a "Gather Wood" point anywhere nearby with trees that isn't your forest space

Now you can restart time and watch your busy little settlers tidy things up. They will be annoyed at you because they haven't got tools or clothes; I demolished the (broken) Tailor and relocated it near the Workshop and Recyclers to speed up production. These little missions aren't super urgent, because you'll almost certainly make the goals as long as you have the relevant building/workers, but they are very useful in providing a buffer of food, water, clothes, and tools, so you don't want to completely ignore them, either.

Secondary priorities are a Hunting Lodge (I put mine by the forestry stuff), an Irrigation Plant by the Bus that covers the fields plus as big an Orchard as you can make in the remaining space, and a Pasture. This is because one of the default animals is Buffalos, which give both meat and milk and will help boost your food diversity. I keep my Hunting Lodge on "Hunt and Capture" so that I don't accidentally end up with a single cow due to drought or whatever. Five cows (or, presumably, four cows and one bull) is really not a big margin of error.

Tertiary priorities are going to be social services (Forum, Market, Medical, a School that isn't in the ass end of nowhere, Decontamination Post) and Research/Expeditions. There are a couple points of interest fairly close by your town, but for now just allot the space and pause the builds. I cleared the roads out of the (now empty) housing valley and stuck my Research and Expedition buildings there. Later on it's also a good place to stick a Mine or two. A Forum is very useful and probably ties with Decon Post for most important to get running ASAP, because some missions are very easy ways to increase Confidence (for instance, the mission Dead Bodies in the Streets always wants you to have one Cemetery and one more Mortician than you have when you accept the mission. You can simply fire someone, take the mission, hire them again, and bam, free Confidence boost).

By now your town should be chugging along. You will probably have a population shortage from the housing dip at the start of the game; since you will probably also have a fair amount of food stockpiled, you can reduce your food workers to one per building. Try to keep at least 6 Water Carriers, more if you can afford them - any fewer and they can't keep up with demand. Likewise, three or more builders is best if you want any construction done in a reasonable time frame.

Somewhere in here you can also remove a bunch of the roads wherever you're not using them. It's all about location, baby. Once I have a solid Food income and safety buffer (~2000) I harvest and demolish the existing fields and roads and combine the four small fields into two medium-sized fields. Same output, half the farmers. Try to time your "demolishing" to a gap between crops, or very early in the planting of a new crop; the field will simply pop out of existence and any crops yet to be harvested are lost.

There's a drought at season 31 or 32 (aka season 6 or 7 from when you started playing), but with a Well or two you shouldn't be too hard up and this is probably when your population low will hit anyway, so there's less demand. Drought also means you can take any Fishers and turn them into Water Carriers, Wellkeepers, or whatever you happen to be short on. Just remember to put them back when the lakes reappear.

If you're following this guide and your town dies anyway, comment and let me know what happened and/or what I should add or change here. I tried to hit the main salient points, but this isn't supposed to be step-by-step, just more of a "here's my experience and what worked for me" approach. Still, I don't want to steer anyone wrong.

• Have 100 settlers

• Have 200 settlers

• Have 350 settlers

Just play the game as normal. Around 100-150 settlers you will probably have a pretty stable town and you can just spam cabins like mad until you're completely overrun with babies. Annoyingly, you cannot double up achievements and get Peter Pan at the same time.

• Have 50 settlers
  
• Build 15 cabins
  
• Have at least 15 dwellings with a positive (green) location score

• Build at least 28 decorative buildings
  
• Equip at least half your settlers with Metal Tools
  
• Build the Forum
  
• Complete 5 Forum Missions

• Reach "Very High" contentedness
  
• Equip at least half your settlers with Radiation Suits
  
• House all settlers
  
• Supply electricity to all dwellings
  
• Complete 5 Forum Missions

Another "Normal Game Plus" mode. When it says "half your settlers" it does count children (I think?) and it will update dynamically as the population changes. Oddly, the requirement to reach high contentedness is apparently not dynamic. As long as you hit it once, you can do whatever you want after that. I'm not entirely sure whether it wants all the green benefits to be active or if it just wants the bar to be green at all, but if you can't get it, set your Cemetery workzone somewhere outside of town and do the Forum mission "Dead Bodies in Our Streets" over and over. "Feast" is also good but I don't know how to force that, if you even can.

If you're having trouble with the electricity, remember you can turn off nearly every building that uses it. You don't have to power your whole town, only the houses and shelters.

• Survive 5 consecutive seasons of drought
  
• Keep at least 10 settlers alive

• Survive 10 consecutive seasons of drought
  
• Keep at least 10 settlers alive

• Survive 15 consecutive seasons of drought
  
• Keep at least 10 settlers alive

I marked this as medium difficulty mostly because you can change the settings to remove a lot of threats and inconveniences. No raiders, no contaminated rain, all the research and all the seeds makes this a lot simpler. Not easy, but easier.

Conservatism is the name of the game in this one. You'll be given five seasons to prepare before each long drought, and you really can't waste a minute of it. Wells are your best friend, because they keep producing at the same rate regardless of the weather, the water is never contaminated, and they're made entirely out of scrap, unlike the Electric Water Pump which needs a bunch of refined materials. However, once you have the Well built, feel free to set it to upgrade immediately; it will keep working while the supplies are gathered, and since you won't have (or shouldn't have) any electronics to give it, it'll stay indefinitely in-progress until you're ready to upgrade.

I recommend pausing the game right out of the gate and setting up all your buildings in planning mode so you can unpause and build them as you need them, even if you normally just wing it. Your priority is a Scrapyard, at least one Recycler (to give metal for a Refinery), 4-6 Cisterns/Water Towers, and 1-3 Wells. Next is food - check the Agriculture Guide on Steam for a diagram of how to maximize the space around your Irrigation Plant. If you like, and depending on your map layout, you can build an extra Well closer to your farmland and limit the Irrigation Plant to only take from Wells, to force your Irrigator to not wander across the entire town. (For some reason these settlers love to take the longest possible path from A to B. Must be all that radiation poisoning.) After that, several Cabins, a Shelter, storage space, so on and so forth. You will also want a Forum to order rationing once the drought hits.

Something I like to do, when I have the population and materials, is to set up a permanent forest for my gatherers, foresters, herbalists, and hunters. This isn't specific to this scenario, but it's most relevant here.

• First, place a Well (or Electric Pump) as close as you can get to the center of where you want your forest, and pause it. Put a Wind Turbine next to it and pause that too. I generally double up unless it rains constantly, so two Wells/Pumps and two Turbines. The Turbines will be less effective right next to each other, but if you only have two they give 209 power each and Pumps take 200 power each, so it works out.
  
• Now pick one particular spot (I like to use roads to make a T-junction from the town to the Wells to the Irrigation Plants, and it makes a handy orange dot marker at the crossroad), and ideally without moving the camera, rearrange the fields of work to all center on that one point. This will help you line them all up without having to eyeball it. The overlap might not be perfect, but it's close enough.
  
• Take a Torch or Streetlamp or whatever other small paused decoration and mark out the top, bottom, left, and right points on your forest circle. This you will have to eyeball and probably adjust a bit, but also it doesn't have to be super exact.
  
• Place four Irrigation Plants roughly equidistant around the circle, so their areas of effect cover most of the ground. Leave the middle of the circle open, as this is where we'll put our well(s), so there's no point irrigating it. You should wind up with a sort of diamond shape in the middle of four circles (plus the cut-ins where the circles don't cover the cardinal points). You can get away with only three Irrigators, but I like four to maximize the space and because it looks nicer.
  
• If you want you can cancel the outer landmarks here, but I like to leave them to help zone more foresters et al later. With this irrigation setup you can easily stack 3-4 of each type of building to cover the same area with no appreciable falloff.
  
• Limit your Irrigators to only take from Wells. When the Pumps are built, turn off Wells too. Now your Irrigators will (probably) default to using the central Well/Pump(s) instead of needlessly hiking across town to take from the Water Towers. As far as I can figure out, settlers can and will drink directly from Wells/Pumps, so you don't need to worry about that.

Some caveats: Irrigation Plants need a massive amount of plastic to build: 30 each for a total of 120, plus the Pumps and Turbines. Make sure you can actually support this before you unpause everything. They also take a massive amount of water to operate, especially during a drought, so keep an eye on it and if your forest constantly yo-yos between green and brown, try dropping the moisture level to medium or even low.

Here's a picture of the layout with the Forester's Lodge work area as reference:



On Jetties and Fishing Huts: these are useful right as you're setting up, to tide you over until your crops/Wells come in, but I would only bother with one of each, maybe two Fishing Huts at the most. They're useless when the lakes dry up, and since the droughts come with sandstorms, your Builders will waste time repairing them and your Fishers will waste time doing nothing of any value whatsoever.

During the actual drought, implement rationing as needed and pull every non-essential worker you can to put on food/water production instead (remember to redistribute them when it ends!). You will probably only make it by the skin of your teeth, but that's okay! It doesn't matter if everyone dies the second the third drought ends, because that's officially Not Your Circus anymore.

• Build 4 Watchtowers
  
• Build 1 Ammunition Factory
  
• Produce 500 metal bullets (buying from traders counts)
  
• Produce 500 rubber bullets (buying from traders counts)
  
• Assign at least 20 settlers to be Militia

• Survive to season [current + 15]

• Survive to season [current + 15]

This is the scenario I had the most trouble with, by far. The raiding parties are ridiculously tough and you don't just have to "survive" them as the blurb says, but successfully kill or scare them off. I wasted a bunch of time trying to be lethal, because you'd think that would be more effective, but no, apparently the maruading hordes who will fight to the last bitter breath are afraid of loud noises. Like, hard same, but come on.

The objectives imply that you should hunker down and wait for the raiders to come to you. You can do that, but it's much harder. The raider and defense system in this game is not incredibly well-designed, so when they say "Watchtower" what they actually mean is "incredibly slow manpowered turret". What we're gonna do instead is create a sort of corridor of Siren Towers along the raiders' route from the east and west and let those do most of the work for us, bolstered by a handful of nonlethal Watchtowers covering the town itself to finish the job. Is this deeply stupid? Yes. Does it work? You bet your ass.

Raiders will make a beeline to the center of your settlement until their "goods looted" bar is full, at which point they will run to the closest available exit. The raid ends when either they've all been killed, their morale bar is depleted, or the raider blob escapes the map with your stuff. This pathing logic, and the convenient lake and mountains surrounding much of the town, means you can pretty easily predict where the raiders are going to go and build accordingly. They're not smart enough to take a different route to avoid the Sirens.

Importantly, the first raider attack is NOT timed. The raiders will obligingly wait for you to build everything and assign your troops before they invade, which is very nice of them. This means you can demolish the existing Watchtowers and essentially just play a medium-hard game until you have everything set up. A few notes on what will kill you if you don't pay attention to it:

• Radioactivity. Get Water Towers, Decon Posts, and ideally iodine and/or a Trading Post up as fast as you can, and forgo Rainwater Collectors for Wells if at all possible. The problem isn't so much outright death from the radiation itself as it is the loss of fertility, which leads into the second immediate problem:
  
• You start with 41 adults and like ten kids, in one Shelter and two Cabins. That equation does not have "sustainable population" on the other end of it. Immediately build 6-10 more Cabins and probably another Shelter as they start breeding. Set the Shelter to "Old and Infertile." You don't have to keep it like that if you end up with homeless settlers, but it forces the game to refresh its logic on who lives there and gives breeding adults priority for the Cabins.
  
• Because you start with so many adults, you will probably end up with something of a population boom and bust cycle. You can fix this by carefully managing your Cabins and Shelters... or by doing nothing and hoping it sorts itself out on its own. Guess which one I picked.

Try to limit your town to within the little... caldera? it starts out in. It's a bit cramped but you can make it work. You'll probably end up with some spillover anyway, but try. Your forestry area will by necessity be outside of that protection, but there aren't many buildings there so it doesn't matter as much.

Oddly, one of the first non-essential things you should build is an Expedition Station. You've got the spare adults for it, and several ruins will give you key Research upgrades that otherwise take a long time to get. Of particular note:

• In the northwest corner is a Military base, a Factory, and the Corner Shop with lights on. The factory assembly line area will give you the Well upgrade that lets you put them right next to each other, and the corner shop has an electrical engineer who will give you a quest that auto-researches electronics manufacturing right off the bat. It also wants you to build Wind Turbines, but it won't give you that for free. The base doesn't have any tech that I know of, but it does have a Research Utensil (the blue microscope) and a bunch of useful things.
  
• In the southwest area are two Greenhouse ruins, one of which has a "sweet smell" coming from it. This one will give you the Hemp Seed, which is incredibly useful.
  
• In a cluster southwest of the town is the Cake Shop, which will research cake for you. This isn't super useful, since you probably don't have a kitchen yet, but it'll save you a research point. It also starts a quest about decontaminating food that's not terribly hard to complete.
  
• To the west is the Nuclear Power Plant, which always has a Research Utensil in it that only requires a Technician (the anvil) badge to get.
  
• To the southeast is a Hospital, which also requires a Technician for a research implement.
  
• Somewhere in the southwest is a Fast Food Diner, with a hatch leading to a tunnel dug by some guy who got kicked out of an Endzone. This starts a quest for Coal Mining, which annoyingly does not give you the research, but it also contains ~23 Expedition Rations, which will save you some time early on.
  
• In the northeast are the Doctor's Office and Bar, the former of which has a creepy scene in the basement but also a Research Utensil, and the latter of which will give you a Wheat Seed, a quest to make beer, and a Research Utensil (I think? someone correct me if not)
  
• In the southeastish is the Clothing Store, which has over 100 cloth to bring back. Not tech, still useful.
  
• I forget where the House Ruin is, but it's got "3 survivors, help!" written on the roof and the top floor has a Research Utensil.

Of the Ruins impeding your construction in the middle of town, the Greenhouse just has some food, so feel free to mark it for salvage without scouting it; the Storage Depot wants a Charcoal Burner but gives some basic resources and an Explorer Badge, so explore or salvage it as you like; and the General Store gives an Explorer Badge and a wider variety of resources and clothing, so it's worth exploring IMO.

Did you know Steam has a character limit for sections of a guide? I didn't.

The first thing we're gonna do is, you guessed it, pause the game and plan our town. You start with no research, so you can't actually build any defenses until you buy that, so instead we're going to plan our town using Water Points (3x3+1) as fake Turbines and Fire Pits (5x5) (from the Halloween DLC) as fake Sirens. Technically the Sirens are 4x4+1, but there's not actually anything else that size to use as a stand-in. Luckily most of these are going in the middle of nowhere anyway, and the ones that aren't can take a line of Tall Shrubs next to them to offset the housing debuff. I didn't really know where I needed them, so I just spammed a big net of Sirens and tracked which ones they broke on the way. The composite image is too big to upload, but here's about how it looks on the minimap:


The other two raids have three blobs of raiders, one from the east and two from the west, but that didn't matter too much IMX. I think in hindsight I'd use this map to build a dirt-road "avenue" with Sirens on both sides, overlapping in the middle or maybe alternating for redundancy. I don't think the effects of Sirens or Barricades stack, except in that obviously if you have two and the raiders destroy one, the second still works (until they destroy that too). So maybe like


where the Xs are Barricades, the Ss are Sirens, and the ts are Turbines? Spaced out so that the whole space in between is covered, of course. I'm lazy and I don't want to do all that again, though, so if you try that lemme know how it works out. Pretty sure the raiders don't use roads, but your workers will get there faster and it'll provide a handy landmark to center on.

Once you've started the first raid, the next two are timed. Honestly I just sprinted this and ignored my settlers complaining about whatever. The Scenario ends the instant the third wave of raiders are off the map. After the first raid, settlers will be added to your town whether you want them or not, and you can trade Rusty scrap or wood for the Siren Tower, Electronics, and Wind Turbine researches. After the second raid, it's more of the same except he gives you Barricades and... something else I don't remember because I already had it. Obviously if you follow this guide you won't need any of it and you don't have to give him anything (unless you want to be nice and/or get rid of some scrap/wood). Set the game on triple speed and cross your fingers. Good luck!

• Store 5000 water

• Have food from 7 different sources
  
• Produce 5000 food

• Plant 150 trees and grow them to maturity

This one is on the hard side of medium, and combines constant drought with a total lack of trees. The only reason it's not insanely difficult is that, again, you can change the settings to cut yourself some slack. The tricky part is balancing your wood supply until you can get an Irrigation Plant, and thus some Orchards, set up. Make sure that when you plan your town, you're in Planning Mode (toggleable on the building info panel just under the icon), because otherwise even if you pause the builds the wood still counts as "reserved" and your settlers are too dumb to use it on something that's not paused. Guess how I know that.

I started with a Cistern, a Well, a Hunting Lodge, a Pasture, a Scrapyard, a Recycler (set to Metal), a Refinery, three Cabins, and a Shelter. If you run out of wood, you can wait on the Scrapyard, the Shelter, and the Pasture. The next most important thing is your Irrigation Plant with Fields and Orchards around it, although make sure to set your Orchards one or two tiles in from the outer edge, as if your settlers think the "starting" corner is on dried-out land they just won't plant anything. We ain't too bright 'round these parts. You're going to want to plant pears, as they have the shortest time to maturity (3 seasons) and it's not the food we need from them but the wood. The wood yield will never max out as a chunk of your field will stay barren, but I got a good ~30 wood from each harvest. You can either try to stagger them to build a stockpile, or just do what I did and cut them down as you need wood. You won't have a Kiln, so your only chronic wood expenditure will be on Tools, which is fairly negligible.

Note that if you're low on people, you can assign a Farmer to plant an Orchard and then pause it. The trees will still grow, so as long as you keep an eye on it and reassign your Farmer when they're mature, you can use that settler for something else in the meantime.

After that, get a Mine for the Coal and upgrade your Cistern/build some Water Towers. Get some more Cabins and a Shelter if you don't have one, so you don't run out of people, then whatever else in whatever order you want.

Orchards sadly don't count for the third goal, so we're going to have to make a forest. Remember the instructions from The Long Summer? Do that and set your Foresters to reforest (with one to cut down and reforest if you need more wood). Pop the game on triple speed, ignore your settlers whining at you, and wait.

• Survive to season 20 (20 seasons of un- or lightly-contaminated rain)

• Survive to season 30 (10 seasons of moderately-contaminated rain)

• Survive to season 45 (15 seasons of heavily contaminated rain)

This one is really misleading, as the blurb makes it sound like there's a single season of each type of rain, and the goals update in 5-season increments, so I thought I was going to be done much sooner than I really was. I benchmarked mine at where the Steam achievement updated. What actually happens is it rains every season and the contamination increases at every increment (10, 15, 20, 25, and 30) from none, to light, to medium, to heavy. In between the achievement checkpoints there's some stretches with, say, two seasons of medium and then back to light, for example.

I said the difficulty was easy, but it's more medium-easy because, like the previous Scenario, you've got to set yourself up right from the get-go. Don't bother with Rainwater Collectors; Well/Pump water is never contaminated. What you absolutely need is a Decon Post, an Iodine Mine, a Medical Facility set to produce Iodine Tablets, and at least one Irrigation Point. Irrigation with uncontaminated water clears radioactivity within its radius, so besides the one you have covering your fields, you can set up a few along the most trafficked routes to save some wear and tear on your settlers and their clothes, as seen here:

(All those little dots are, amusingly, Scrap Piles that need a Scrapyard, and buildings, which are apparently immune to radiation. The More You Know!)

You can postpone the Mine until about season 30 or so if you need to, but sooner is better.

Optionally, you can set up a Weather Station. This isn't super necessary, but it's nice to see the forecast and it gives you the option to cover your fields (and the Rainwater Collectors you don't have) if you want to be extra sure.

• Store 10k water
  
• Store 5k food
  
• (will subtract 9k water and 4k food on completion)

• Store 15k water
  
• Store 7.5k food
  
• Store 100 Activated Carbon Masks
  
• (will subtract 14k water, 6.5k food, and 100 Masks on completion)

• Store 20k water
  
• Store 10k food
  
• Store 150 Activated Carbon Masks
  
• Store 1.5k Medication
  
• (will subtract 19k water, 9k food, 150 Masks, and 1.5k Medicine on completion)

This one isn't too hard, just tedious. Since you can turn off diseases and rain contamination, you can build two Tailor Shops and set one to Face Scarves and the other to Activated Carbon Masks, and then outlaw the Masks from the Town Center so the settlers don't use them up. Honestly the only hiccup I had was I forgot that Medical Facilities can only store about 1000 Medicine, but I just sent some to the Market and then production resumed. If you want to make sure you have extra food and water as a buffer you can delay production of the masks until you have more than what the mission will take.

• Survive to season 75

• Survive to season 150

• Survive to season 250

Remember when I said the last one was tedious? I lied. This is tedious. It's just a normal game with basically all the hazards turned off. I got everything built and my town sustainable at around season 80 and then left to go watch a movie. One season is about 60 seconds at triple speed, so you can come back in about an hour and a half to progress the quest.

You made it and (hopefully) have all the Scenario achievements! If this guide helped you, consider leaving a thumbs up, because it's free and I like endorphins. Keep on surviving!