Why This Page Exists
If you've landed on a forum post, a mod readme, or a download page and found yourself unsure what something means, this page should clear it up.
CC - Custom Content
In the Sims community, CC means Custom Content - any file made by a player (not Maxis/EA) that adds something visual to the game. This includes custom clothing, hairstyles, skin tones, furniture, wall coverings, floors and objects.
CC is the catch-all term for things that change how the game looks without changing how it plays. A new outfit is CC. A custom sofa is CC. A wall pattern is CC.
This is the main source of confusion. The Complete Collection was the original boxed set of The Sims 1 with all expansion packs included, released in 2002. Players and stores often abbreviated it to "The Sims CC" or just "CC". If you're reading an old forum post or mod readme from the early 2000s and it mentions "CC", the author might mean the Complete Collection rather than custom content - read the context carefully. A line like "works with Sims CC" most likely means the Complete Collection. A line like "drop this file in your CC folder" means custom content.
Mod
A mod is a file (or set of files) that changes how the game behaves. In Sims 1, this usually means a modified .iff file that alters an object's price, the carpool timing, how relationships decay, how quickly skills are gained, or similar gameplay values.
The distinction between a mod and CC gets blurry in Sims 1. A custom chair that looks different but works the same as the base game chair is really CC. A chair that's been edited so Sims gain Body skill by sitting in it is a mod. In practice, the community often uses "mod" and "CC" interchangeably for any downloaded file, so don't read too much into which word someone uses.
Hacking
In the Sims community, "hacking" has nothing to do with breaking into systems or doing anything illegal. It refers to opening and editing the game's object files - specifically .iff files - to change how objects work.
When someone says they've "hacked" an object, it means they've opened it in a tool like IFF Pencil 2, modified the values or scripts inside, and saved a new version. A "hack" is the resulting modified file.
The term comes from the earliest days of Sims modding when this kind of editing was novel and required genuine technical knowledge. It stuck even as the tools became much easier to use. Today "hacking" and "modding" are used interchangeably when people talk about editing game objects, even if no coding is involved.
IFF & FAR Files
An .iff file is the core file format for Sims 1 objects. Every buyable item, piece of furniture, interactive object and most gameplay modifications exist as .iff files. The format is actually quite old - it was developed by EA and used across many of their games in the 1980s and 90s before The Sims adopted it.
An .iff file is essentially a container that holds multiple different resources together: the object's 3D sprites (the images that make it look right), its BHAV scripts (the code that tells the game what the object does), its price and category information, its name, and more. When modders talk about editing an object, they mean editing the contents of its .iff file.
A .FAR file is a bundle that contains multiple .iff files packed together. Think of it like a zip file, but one the game can read directly without you needing to unpack it. Many older mods and all of the Sims 1 expansion pack content is distributed as .FAR files.
Most modern mods come as loose .iff files rather than .FAR files, but you may still encounter them. Both go in the same Downloads\ folder and the game handles them the same way.
Skins
In Sims 1, "skins" refers specifically to the image files that make a Sim look the way they do - their clothing, body shape appearance, facial features and hair. These are bitmap (.BMP) files that get painted onto the 3D Sim body and head models.
Unlike later Sims games where clothing and hair are separate items with meshes, in Sims 1 the entire Sim is essentially one texture. A "skin" for an outfit means a complete body image - top, bottom and shoes all in one file. Hair is painted directly onto the head texture rather than being a separate item. This is why skin files must go in GameData\Skins\ with no subfolders - the game scans that one directory directly at load time.
When you see "skin download" on an old Sims 1 site, it means a new outfit, hairstyle or character appearance - not a separate mesh or item.
Everything the game needs to know about a skin is encoded in its filename. The first letter tells the game what clothing category the skin belongs to - which dresser drawer it appears in, whether it's buyable at a clothing rack, and which expansion unlocked it.
| Prefix | Type | Where it appears | Requires |
|---|---|---|---|
| C | Cranium (Head) | Create-A-Sim head selection | Base game |
| B | Body (Everyday) | Dresser - everyday clothing drawer | Base game |
| L | Lingerie (Pajamas / Sleepwear) | Buyable at clothing rack - sleepwear section | Hot Date |
| F | Formal | Buyable at clothing rack - formal section | Hot Date |
| S | Swimwear | Buyable at clothing rack - swimwear section | Hot Date |
| W | Winterwear | Buyable at clothing rack - winterwear section | Vacation |
| H | High Fashion | Buyable at clothing rack - high fashion section | Superstar |
| H | Hand files | Sim's hand texture (separate from body) | Base game |
| xskin- | Mesh file (.skn) | Defines the 3D shape - paired with BMP textures | Base game |
After the type prefix, the rest of the filename encodes: gender (f = female, m = male), age (a = adult, c = child), body type (3 letters), skin tone (lgt / med / drk), then an underscore and the outfit name. For example: Lfa fit lgt_MySleepwear.bmp = Lingerie, female adult, fit body type, light skin tone.
Note on H: Both High Fashion and hand files start with H. The game distinguishes them by context - hand files are referenced directly in character files, while High Fashion skins appear in the clothing rack like other buyable types.
The L, F, S, W and H prefixed skins are "buyable" - they don't appear in your Sim's home dresser but are instead purchased from a clothing rack on a community lot (introduced in Hot Date). This means your Sims have to visit a shopping lot to buy them, just like in real life.
In the original game and older installation guides, buyable skins were told to go in a separate SkinsBuy\ folder rather than the main Skins folder. In the Legacy Collection, this folder exists at ExpansionShared\SkinsBuy\.
ExpansionShared\SkinsBuy\ folder is the correct location for buyable skins (L, F, S, W, H prefix) in the Legacy Collection. Dropping them in the regular GameData\Skins\ folder may work for some, but using the dedicated SkinsBuy folder is the more reliable approach. The no-subfolders rule applies to both locations.Complete Collection vs Legacy Collection
The Complete Collection was a boxed retail version of The Sims 1 released in 2002 that included the base game and all expansion packs available at the time. It was later updated to include Makin' Magic. Most players who played Sims 1 in its original era will have had the Complete Collection rather than individual discs.
Because it was abbreviated as "CC" or "Sims CC", this causes confusion when reading old modding guides that also use CC to mean custom content. Context is everything - if a readme from 2002 says "tested with Sims CC", it means the Complete Collection. If it says "put CC files in this folder", it means custom content files.
The Legacy Collection is the 2025 re-release of The Sims 1, available on Steam and the EA App. It includes the base game and all seven expansion packs, updated to run on Windows 10 and 11. This is the version this guide is written for.
The internal save file folder is named "The Sims 25" (referencing the 25th anniversary), which is why some paths on this guide reference that name. The Legacy Collection is functionally identical to the Complete Collection for modding purposes - the same folders, the same file types, just different root paths.