The Sims 3 'Build A City' Challenge
Goal: Begin with an empty neighbourhood and develop it into a city over several generations.
My version of this challenge is detailed below, as well as in my Sims 3 Build A City Challenge Template, updated in early 2026 to include better instructions, automatic tracking features, and more reference information. It is completely free for anyone to use!
This challenge is based on the rules by Tom Simkins (on The Sims Forums) / Hutson0 (on the EA Forums), with some additions and changes based on alternate rules to include more expansion packs by Natasha699 (on Mod The Sims) / (on The Sims Forums / SkiesUpHigh on EA Forums).
Preparation for the Challenge
Neighbourhood
Before you begin, note that it might be helpful to create a back-story to the neighbourhood. In my case, I took the back-story of Appaloosa Plains – that the sleepy ranching town was in decline - except instead of nouveau riche coming in and causing a conflict between old and new, the town deteriorated and was essentially abandoned. The "government" responded by clearing out all of the buildings except a Victorian-style boarding house, which it refurbished. This explains the presence of the NPC household, but we'll get to that in a moment.
First off, choose a neighbourhood that has a map that you want to use. This could be either a pre-made neighbourhood or a custom made one. Next, go to Edit Town and delete all lots in the neighbourhood. You can leave the lots that have no/little "Sim-made" objects on them (purely nature).
Since you begin with one community lot, I recommend it be a fishing spot or a garden to make up for the lack of plants. You should set it to "No Visitors Allowed" and only let a Sim go there to get seeds once per week, maximum. You may want to use the DebugBuy cheat to find fish and plant spawners for your starter lot.
The NPC Household
The first thing you will create is the NPC household. The household will represent the townies that you cannot control – you will not play this household. It will consist of 4 males and 4 females, all Young Adults or Adults. You create them in "Create A Sim" by creating a person and randomizing their traits, favorites and Lifetime Wish (LTW). You may customize their looks and voice, but you're not supposed to know their traits. Repeat the process until you have your household of 8, with 4 of each gender Sim. You may create relationships between up to 3 of them, but I personally did not as I wanted to have more variety rather than a set of siblings.
When back at the neighbourhood view / in Edit Town mode, you may build their house as you like. Feel free to give it a theme – a boarding house like I did, a hotel, an asylum, government housing, or whatever you'd like – but remember you will not play this household.
You can move the NPC family into the house using the freeRealEstate cheat.
Rules for the NPCs
You may not play the NPCs unless you move them into your household.
No moving NPCs in just to move them out… that’s cheating.
One or more of your playable Sims must befriend them and "Ask to Move In", or marry them. When you want to move them out into their own Household, they must either move into a pre-built house you pay for, or you can pay for an empty lot and send them with 'family funds' equal to or greater than what they moved in with.They do count towards your Population. (Population count will be explained below.)
However, their deaths only count (towards unlocking the Graveyard – more on this below) if you moved them in.
The NPCs are not automatically replaced. You cannot create a new one each time you move one out of the NPC Household, nor if they somehow die before you can move them into an Active/Playable Household. That would inflate your Population count. You may only add 1 new NPC (randomized traits, favourites and Lifetime Wish) to the NPC Household for every 5th Community Lot you earn/build.
Fires that occur on the lot while you are on it count towards the fire limit.
Lastly, you may only visit the actual NPC Household after your Sim becomes Best Friends with at least one of the NPCs.
At this point, you should have a mostly blank neighbourhood with only a few “parks” and an NPC household of 8 people. If you do, you may continue.
Your Sim Founder
Time to create your Sim… Just do it like normal. The only difference is that you have to move them into an empty lot since no houses or apartments exist yet.
Note: Any Sims after this 'Founder' may move into pre-built houses.
Settings / How to Play
Story Progression – You can choose to play with Story Progression ON or OFF.
Story Progression OFF & Aging OFF – This style is most similar to the Sims 2 style. As your neighbourhood expands, you should play EVERY household for the same amount of time.
In this option, you should play each Playable Household for 1 week. After that week, switch households. Once all Households (except the NPC household) are played, the Round/cycle has ended and a new one can begin.
You will have to keep track of your Sims' ages (or find a mod that makes aging similar to The Sims 2) and manually age them with birthday cakes or by clicking on them with TestingCheatsEnabled true.
You may also have to keep track of your Households' funds once you begin Rounds/cycles. I found that the game would make weird changes to Household funds in some cases. Simply note the amount of funds at the end of that Household's week you play, and when you return to that Household for the next round/cycle, check your Sims' inventories for anything they shouldn't have (I've found cars often get given to Sims not in your Active Household) and sell/delete those that don't belong. Then use the familyfunds cheat to set the funds to what you previously recorded.
My Sims 3 Build A City Challenge Template has a 'Household/Age Tracker' sheet/tab to keep track of your Rounds/cycles, Active Households, Sims' ages, Households' funds, and more.
Story Progression ON & Aging ON – In this option, you may change Households at will for the duration of the challenge. Play out the lives of the Sims you find interesting, strategically choose to play Sims whose Lifetime Wishes or traits could advance the community in some way, or simply free play for fun.
Lifespan – You can choose any lifespan you want. It is recommended that you play this challenge either at the default Lifespan (Normal/90 Days) or the long Lifespan (Long/190 Days) since you are probably going to count the days manually.
I started with ‘Normal’ lifespans but switched to custom settings (totalling 150 Days) so my Sims’ Life Stages would be more aligned with real-life ages (e.g. Baby and Teen are shorter, others are longer. Every “year” of age is ~2 Sim Days).
The (Actual) Challenge
The goal of this challenge is to create a city with a population of 50,000 or more people. Of course, you will not be playing 50,000 Sims. That would be extreme!
Instead, a simple formula is used:
Population = # of Playable and NPC Sims X Sim Multiplier
In words: The Population of the city is the number of Sims you play combined with the number of Sims still in the NPC Household, times the Sim Multiplier (SM).
Note: Since NPCs are included in the Population count, you may only add 1 new NPC (randomized traits, favourites and Lifetime Wish (LTW)) to the NPC Household for every 5th Community Lot you earn/build. You may not simply replenish them as you move them into Playable Households or if they somehow die before you move them out.
Sim Multiplier (SM)
Now, you may be wondering how to get the Sim Multiplier (SM). The SM begins at 1 and is raised by:
+1 for the first Community Lot you earn
+1 when you reach a total of 5 Community Lots
+1 for every 5 additional Community Lots
+1 when the first Sim invests in a business
+3 when 4 businesses have investors
+5 when all 11 businesses have investors
+2 when the first Sim owns 1 business outright
+6 when Sims own 4 businesses
+10 when all 11 businesses have owners
+5 for each ‘Airport’ you unlock
How to Unlock Lots, Careers and Services
If the neighbourhood is all but a blank slate, how do you add lots, invest in businesses, or get employed?
What makes this challenge difficult is that pretty much all buildings and jobs, as well as most services, are "locked" when you begin. Your Sims, number of Households and Population must hit certain milestones to "unlock" them. These requirements will be explained in detail in the following sections (and in the 'Unlock Requirements' sheet of my Sims 3 Build A City Challenge Template).
Careers are often limited to a certain number of Sims or Sims with certain skills until they are "fully unlocked." Often, a Career must be "topped," in other words, a Sim must reach Career Level 10, to fully unlock it for the community. When a Career is "fully unlocked," that means any Sim – and as many Sims as you'd like, unless otherwise stated – can join/accept a job in that Career.
Throughout the challenge, the number of Community Lots must be less than the number of Households. When you begin, you have 2 Households (Founder and NPC) and 1 Community Lot. That means you must add another Household before you can add another Community Lot.
Increasing Households
You can increase the number of Households in the following ways:
1. Getting and using Create-A-Sim (CAS) points (highlighted below under ‘Unlocking Community Lots’). CAS points can be used right away or "saved up" to use at the same time to create a family/Household of 2 or more.
2. Having or adopting children who move out when they are a Young Adult or older.
3. Moving out a Sim who is a Young Adult or older.
Note: If the Sim joined your Playable Household as an NPC, when you want to move them out into their own Household, they must either move into a pre-built house (you pay for), or you can pay for an empty lot and send them with 'family funds' equal to or greater than what they moved in with.
Unlocking Community Lots
A Community Lot can be placed at any time, but only one can be added per Round/cycle of gameplay. The number of Community Lots in play must remain lower than the number of Households. What type of Community Lot you add depends on what you have unlocked. I've tried to list them in roughly the order you could unlock them.
The list will seem quite daunting at first – as will my Sims 3 Build A City Challenge Template – but I find the template spreadsheet formatting a bit easier to navigate as a reference. The ‘Unlock Requirements‘ sheet has the same information as the list below, and the ‘Unlock Tracker’ sheet can automatically use your input about your gameplay to show you what you’ve unlocked.
Once you unlock a Community Lot, you can place a lot that came with the game, that you download from The Exchange or elsewhere, or that you create yourself. If creating a lot yourself, you may want to use the DebugBuy cheat to place special objects and spawners.
(You may use of rabbit hole Custom Content (CC) such as aa6x7's "rugs", cazarupt's rugs or mrfatcatstuff's complete rug set, but you still must meet the regular unlock requirements for the relevant lot/building type.)
You may place lots with multiple buildings/rabbit holes on the same lot (e.g. the combined Bookstore and Spa, Hospital and Science Center, School and Stadium, etc.) if you have unlocked all of the relevant buildings/lot types.
Expansion Pack requirements override the normal requirements unless otherwise stated.
Colour Code:
Base Game
World Adventures*
Ambitions
Late Night
Generations*
Pets
Showtime*
Supernatural
Seasons
University Life*
Island Paradise
Into the Future*
The Sims 3 Store content
If you don't have the Expansion Pack or Store content listed, ignore that coloured script.
Tip: If you use my spreadsheet template, you can ignore or apply “strikethrough” formatting for Expansion Pack or Store items you don't have.
Unlocks by:
Skill Levels
Events
# of Households
Population
Community Lot – Requirements
Small Parks & Beaches – Always unlocked, but limited by 1 Community Lot per Round rule.
Dog Parks – 5+ Dogs live in Households.
Cat Jungles – 5+ Cats live in Households.
Playground (equipment, for dedicated playground park lot or to add to other lots) – 10 Sims are in the Child life stage at the same time.
Military Base – 3 Households. Unlocks 1st Military Career position.
+1 Military job every 3 Households.
Consignment Store – 2 Sims have maxed a creating skill (e.g. Painting, Writing, Photography, Sculpting, Inventing, Artisan).
Elixir Consignment Store – 3 Sims have maxed the Alchemy skill OR 3 Supernatural Sims (e.g. Witches, Werewolves, Zombies, Fairies, Vampires, Genies, Aliens, playable Ghosts) with 3+ Alchemy skill live in town.
Fortune Teller Wagon – 3 Witches and/or Genies live in town.
Unlocks the Fortune Teller/Clairvoyant Career for Witches and Genies, and every Sim with both 5+ Charisma skill and the “Supernatural Fan” trait.Fortune Teller/Clairvoyant Career fully unlocked after 3 Sims top it.
Street Market (Al Fresco Street Market) – 2 Sims have maxed the Gardening skill AND 1 Sim has maxed the Cooking skill.
Arboretum & Greenhouse (Stones Throw Greenhouse) – 3 Sims have maxed the Gardening skill AND 1 Sim has completed 1+ Gardening skill challenge (e.g. Master Planter, Botanical Boss, Master Farmer).
Gym / Workout Facilities – 5 Sims have maxed the Athletic skill.
Dojo / Martial Arts Studio – 3 Sims have maxed the Martial Arts skill.
Nectary – 3 Sims have maxed the Nectar Making skill.
Art Gallery – 4** brilliant or better paintings AND 4 brilliant or better sculptures are created but are not sold. These must be placed in the Art Gallery.
**8 paintings if you do not have the Ambitions Expansion Pack.Prism Art Studio – An Art Gallery has been built AND 2 Sims have maxed the Painting skill AND 1 Sim has maxed the Sculpting skill.
Skylight Studio for the Performing Arts – An Art Gallery has been built AND 2 Sims have maxed the Painting skill AND 1 Sim has maxed the Athletic skill.
Bakery (Deliciously Indulgent Bakery) – 5 Households AND 3 Sims have maxed the Cooking skill.
Laundromat – 10 Households without washing machines or dryers.
Salon / Tattoo Parlor – 10 Households AND 2 Sims have maxed Charisma skill. Unlocks 1st Stylist Career position.
+1 Stylist job for every 10 Households.
Bars:
Dive Bar or a Local Watering Hole – 10 Households.
Dive Bar Criminal – 10 Households AND 1 Sim has topped the Criminal Career.
Sports Bar – 15 Households AND 1 Sim has topped the Athletic Career.
Clubs:
Dance Club – 20 Households.
Disco Club – 25 Households AND 5 Sim have maxed an instrument skill (e.g. Guitar, Bass, Drums, Piano, Violin, Laser Rhythm-a-con).
Sports Bar – 15 Households AND 5 Celebrities with 3+ Star Level.
Lounges – 5 different Sims top 1+ careers OR 5 Celebrities with 3+ Star Level. Unlocks 2 CAS.***
Vampire Lounge/Bar – Requirements for Lounge AND 3+ Vampires** live in town. Unlocks 2 CAS.***
**If you do not have the Supernatural Expansion Pack, you can ignore the 3+ Vampires requirement.Future Lounge – 5 different Sims top 1+ careers (including 1+ Science Career) AND 1+ Sim has maxed the Bot Building skill or a Sim has Invented 1+ SimBot. Unlocks 2 CAS.***
Graveyard – 20 Sims die. Unlocks Mausoleum and associated part-time jobs.
Ghost Hunter Career unlocked after Graveyard and Science Center are placed. Only 1 Sim in Ghost Hunter Career at once.
Religious Buildings (e.g. custom Church, Temple, Mosque, etc.) – 10 Weddings or Marriages AND Graveyard has been unlocked and has either already been placed or will be on the same lot as the Religious Building.
Bistro / Diner – Every Sim who completes 2 of the Cooking skill challenges (e.g. Star Chef, World-Class Chef, and Menu Maven) is eligible for a Culinary job.
After the Culinary Career is first topped, any Sim with max Cooking skill is eligible for a Culinary job.
Culinary Career fully unlocked at venues where it has been topped by 1+ Sim employees.
Stadium – Every Sim who completes all Athletic skill challenges (e.g. Body Builder, Marathon Runner, and Fitness Nut) is eligible for an Athletic job.
After the Athletic Career is first topped, any Sim with max Athletic skill is eligible for an Athletic job.
Athletic Career fully unlocked after 3 Sims top it.
Pet Store / Adoption Center – 15 stray cats and/or dogs are adopted into Households.
Horse Ranch / Training Grounds – 5 Horses AND 5 Sims with 3+ Riding skill.
Equestrian Center – 10 wild Horses tamed OR 20 Foals bred OR 5 Sims with 10 Riding skill, 3+ of which have 3+ Jumping skill.
Criminal Hideout / Warehouse – 100 Population. Unlocks 1st Criminal Career position.
+1 Criminal job for each Sim who tops the Criminal Career.
Hangout – 1 unlocked at Population levels 100, 1000 and 30,000.
If you have the University Life EP, also unlock 1 at Population levels 5,000, 10,000 and 20,000 AND can place instead:
Java Hut – 1+ Sims have completed University AND a Bistro, Diner or Bakery has been built.
University Hangout – 5+ Sims have completed University.
Nerd Shop – 5+ Sims have completed University AND the Science Center has been built.
Rebel Hangout – 5+ Sims have completed University AND an Art Gallery, Salon/Tattoo Parlor or Dive Bar has been built.
Arcade – 5+ Sims have completed University AND the Theatre or Cinema has been built.
Supernatural Hangout – 15 Supernatural Sims live in town, with at least 3 types represented (e.g. Witches, Werewolves, Zombies, Fairies, Vampires, Genies, Aliens, playable Ghosts).
Library – 250 Population.
Vault of Antiquity – a Library has been built AND 3 Sims have maxed the Alchemy skill.
School – 250 Population. Unlocks 1st Education Career position. Unlocks 5 CAS.***
+1 Education job for every 250 Population.
Boarding School – Always unlocked, but travel penalties apply.*
University – a School has been built AND a Sim must complete high school to enroll in University AND travel penalties apply.*
Police Station – a Sim tops the Criminal Career OR 500 Population and 3+ burglaries occur. Unlocks 1st Law Enforcement or Investigator Career position. Unlocks burglar alarms.
+1 Law Enforcement or Investigator job for each Sim who tops the Criminal Career.
If you do not have the Ambitions Expansion Pack:
(requirements above) AND 3 fires have occured on residential lots. Unlocks fire alarms.
Fire Station – a Police Station has been built AND 3 fires have occured. Unlocks 1st Firefighter Career position. Unlocks fire alarms.
+1 Firefighter job for every 3 fires that occur.
Science Center – 3 Sims have been electrocuted AND 1 Sim has been abducted by Aliens. Unlocks Science Career for all Aliens and each Sim who becomes an Adult with 10 Logic skill and 10 Inventing skill.
After the Science Career is first topped, it is fully unlocked.
Ghost Hunter Career unlocked after Graveyard and Science Center are placed. Only 1 Sim in Ghost Hunter Career at once.
Spa – 500 Population.
Community Pool – 500 Population.
Show Venues:
Coffeehouse – 500 Population OR a Java Hut has been built. (Can add Showtime Expansion Pack items to the Java Hut and change its lot type to Coffeehouse, if you want.)
Live Show Venue – 750 Population.
Private Venue – 1,500 Population.
Big Show Venue – 5,000 Population.
City Hall – 1,000 Population. Unlocks 1st Politics Career position. Unlocks Self-Employed Careers.**
**except the Daycare Career. Daycare jobs are based on the number of Toddlers in town.+1 Politics job for every 4,000 Population.
+1 Daycare position for every 5 Toddlers.
Architectural Design Career requires City Hall is built AND 8+ Households. Only Sims with 10 Painting skill are eligible.
+1 Architecture job per 8 Households, for Sims with 10 Painting skill.
Big Parks & Beaches – A Sim in the Politics Career becomes the Mayor (Level 7).
Festival Grounds – A Sim becomes Mayor (Politics Career Level 7) AND 3+ Sims have the “Loves the Outdoors” trait.
Business Park – A Sim becomes Mayor (Politics Career Level 7) AND 3+ Sims have topped the Business Career.
Hospital – 1,000 Population. Unlocks 1st Medical Career position. Unlocks 1 CAS.***
+1 Medical job for every 5,000 Population.
Bookstore – 1,000 Population. Unlocks associated part-time jobs. Unlocks 1 CAS.***
Bus Station (not an in-game lot type; you can make your own, put some sort of placeholder, or simply record that it’s been “placed”) – 1,000 Population. Lowers travel penalty to $1,000.* Only 1 may be placed; can share a lot with another building. Unlocks 2 CAS.***
Business Building / Office – 1,000 Population. Unlocks 1st Journalism Career postion. Unlocks Business Career positions for Sims in families / Households that own 2 lots or own shares in 3 businesses.
+1 Journalism job for every 5 Sims who top ANY Career.
+1 Business job for each Sim at Level 5+ of the Business Career.
Casino (The Lucky Simoleon Casino) – 1+ Sim has topped the Business Career AND 1+ Sim has topped the Criminal Career.
Film Studio – 3 different Sims top 1+ Careers AND 2+ Sims have completed the Prolific Writer skill challenge. Unlocks 1st Film Career position and associated part-time jobs. Only Sims with 10 Charisma skill or 10 Writing skill are eligible for Film jobs until the Film Career is 1st topped.
+1 Film job each time 3 different Sims top 1+ Careers OR 2 Sims complete the Prolific Writer skill challenge.
Film Career fully unlocked after both the Acting and Directing branches are each topped at least once.
Junkyard – 2,000 Population unlocks 1st Junkyard.
4,000 Population unlocks 2nd Junkyard.Supermarket / Grocery Store – 3,000 Population. Unlocks associated part-time jobs. Unlocks pizza delivery. Unlocks 1 CAS.***
Theatre – 3,000 Population OR a Sim completes the Money Maker (instrument) skill challenge. Unlocks Music Career positions for every Sim with a maxed instrument skill (e.g. Guitar, Bass, Drums, Piano, Violin, Laser Rhythm-a-con).
Music Career fully unlocked after any branch is 1st topped.
Le Cinema Plumbob – a Theatre or Film Studio has been built AND 1+ Hangout or Bar has been built.
Resort /Serenity Retreat – 5,000 Population AND 1+ Beach has been built.
Chinese Garden – 5 Householdsreach Visa Level 3 (have 1+ Level 3 Visas).
Bot Emporium – 5 Sims have maxed the Bot Building skill OR 15 Sims with the “Bot Fan” trait are living in town.
Cafeteria – 5,000 Population AND 3+ Sims have topped the Culinary Career.
Stellar Observatory – 10,000 Population AND the Science Center has been built.
Plumbot Competition Arena – 10,000 Population AND the Bot Emporium has been built.
Subways & ZEPHYR Stops – 20,000 Population.
Airport (not an in-game lot type; you can make your own, put some sort of placeholder, or simply record that it’s been “placed”) – $1 million in "donations" or taxation from Sims (can be deducted with the familyfunds cheat). Eliminates travel penalties.* Unlocks 5 CAS.***
*Travel penalties: Travel to World Adventures locations, the Future, concerts/shows in other cities, Boarding School, or University starts with an extra cost of $2,000 per trip/school. After paying this fee on top of the regular in-game price, Sims can travel, use time machines, play shows and attend Boarding School or University as usual. (You can use the familyfunds cheat to deduct the additional fee.)
*** Unlocking CAS points means you may use Create-A-Sim (CAS) to create any Sim you would like, including selecting their traits, favourites, and Lifetime Wish (LTW). 1 CAS = 1 Sim.
These points can be used right away or “saved up” to use at the same time to create a family/Household of 2 or more.
The ‘Unlock Tracker’ sheet/tab of my Sims 3 Build A City Challenge Template includes automatic tracking of CAS points and when NPCs can be added, travel penalties, when Careers are unlocked, and more. It is completely free to use!
Unlocking Services
Newspaper Delivery – Always unlocked.
Baby-sitter – Always unlocked.
Adoption Service – Always unlocked.
Repair Services – Unlocked at 500 Population.
Maid – Unlocked at 500 Population.
Butler – Unlocked at 10,000 Population.
Pizza Delivery – Unlocked when Supermarket / Grocery Store is built.
Burglar Alarm – Unlocked when Police Station is built.
Fire Alarm – Unlocked when Fire Station is built. (If you don’t have the Ambitions Expansion Pack, see additional requirement for Police Station.)
Boarding School – Always unlocked, but travel penalties apply (see *Travel Penalties note above).
University – School has been built AND the Sim must complete high school to enroll in University AND travel penalties apply (see *Travel Penalties note above).
The ‘Unlock Tracker’ sheet/tab of my Sims 3 Build A City Challenge Template includes a section that shows which Services have been unlocked, as well as sections for Community Lots, Careers, travel penalties, and more. It’s completely free to use.
Please do not redistribute the template without credit, nor try to monetize it.