Installing Mods - Sims Legacy Collection Guide

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Overview

Modding works differently here than in other Sims games

The Sims Legacy Collection handles mods differently to every other game in the series. Rather than dropping files into a Documents folder like you might expect, all custom content and mods live inside the game's actual install directory. This applies whether you're on Steam or the EA App - the subfolder names are identical between both versions, only the root path changes.

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Steam Install Paths

Right-click the game in Steam → Manage → Browse local files

C:\Program Files (x86)\Steam\steamapps\common\The Sims Legacy Collection\

File Type	Subfolder	Notes
.iff & .FAR (objects, hacks)	Downloads\	Most mods go here
.BMP .CMX .SKN (skins)	GameData\Skins\	⚠️ No subfolders!
.WLL (wall coverings)	GameData\Walls\
.FLR (floor tiles)	GameData\Floors\
Game file overrides	GameData\Objects\	Only for mods replacing base files
Expansion overrides	ExpansionPack#\	# = expansion number 1–7

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EA App Install Paths

Right-click in EA App → Manage → Open install folder

C:\Program Files\EA Games\The Sims Legacy\

Same subfolder names as Steam - Downloads\, GameData\Skins\, GameData\Walls\ etc. Only the root path differs.

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File Type Quick Reference

.iff Object File

The most common mod format. Contains object data, interactions and behaviour. Goes in Downloads\ unless the readme specifies otherwise.

.FAR Container File

Bundles multiple .iff or .xa files together. Also goes in Downloads\.

.BMP .CMX .SKN Skin Files

Custom clothing, hair and head textures. Everyday skins (prefix B or C) go directly in GameData\Skins\ - no subfolders. Buyable skins (prefix L, F, S, W, H) go in ExpansionShared\SkinsBuy\ - also no subfolders.

.WLL / .FLR Decor Files

Custom wall and floor textures. Goes in GameData\Walls\ or GameData\Floors\. Subfolders are supported in both.

Roof textures

Goes in GameData\Roofs\ directly - no subfolders.

.iff Game File Override

Mods that replace an existing base game file go in GameData\Objects\, not Downloads\. The readme will specify this.

.iff Expansion Override

Mods targeting a specific expansion's files go in ExpansionPack#\ where # is the expansion number 1-7. Check the readme.

.iff Downloaded Lots

Lot files go in UserData\Houses\ for your default neighbourhood, or UserData1\Houses\, UserData2\Houses\ etc. for others.

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Save File Location

C:\Users\%USERPROFILE%\Saved Games\Electronic Arts\The Sims 25\

Back this folder up before installing any mods! Some mods can make permanent changes to save data that persist even after the mod is removed.

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Installing Old Mods (2000-2003)

Most old mods still work - just translate the path

Old mod instructions will reference: C:\Program Files (x86)\Maxis\The Sims\

Simply replace that with your Steam or EA App path above. All subfolder names are identical.

Example:
Old path: Maxis\The Sims\ExpansionPack5\ New path (Steam): The Sims Legacy Collection\ExpansionPack5\

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Important Rules

No subfolders for skins - in either folder. Everyday skin files (.BMP/.CMX/.SKN with prefix B or C) must sit directly in GameData\Skins\. Buyable skins (prefix L, F, S, W or H) must sit directly in ExpansionShared\SkinsBuy\. Any subfolder in either location and the game won't read them.

Unzip everything first. The game cannot read .zip files. Always extract before moving files into place.

Add one mod at a time. Install one mod, test in game, then add the next. Makes identifying problems much easier.

Check for virus warnings. Many Sims 1 mod files are 20+ years old. Scan with your antivirus before opening, especially from lesser-known sites.

⚠️ Know the limits before you go big on CC. The original Sims 1 engine had several built-in caps that can cause strange behaviour or crashes if you exceed them. The Legacy Collection has not officially confirmed these have been lifted, so treat them as still active unless you find community reports saying otherwise.

Build Mode objects (doors, windows, fences, stairs etc.) are capped at 200 items per category on the base game only. With the Unleashed expansion, this rises to 2,000. Exceeding the limit causes visual glitches - too many fences makes pool ladders disappear, too many plants makes fireplaces turn into plants, and so on.
Walls are capped at 90 on the base game, rising to 65,000 with Livin' Large or later.
Floors are capped at 63 on the base game, also rising to 65,000 with Livin' Large or later.
Downloads folder size - community testing found keeping it below around 2.5-3 GB helps avoid random crashes. FAR file capacity is estimated at around 2 GB.
Skins - there is no confirmed hard limit on the number of skin files, but players have reported crashes with very large collections (3,000+) while smaller sets (a few hundred) work fine. If you have a large skin collection and the game is crashing, try splitting it into smaller batches to identify the cause.

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Step-by-Step: Installing Your First Mod

Back up your save files before installing any mods. Your neighbourhood saves are stored at C:\Users\%USERPROFILE%\Saved Games\Electronic Arts\The Sims 25\ - copy that folder somewhere safe before you start. Some mods can make permanent changes to save data that persist even after the mod is removed.

Download the mod

Download from a trusted site (see the Download Sites page).

You'll usually get a .zip file - if so, continue to step 2. If the download gives you the mod files directly (e.g. a .iff, .FAR or .BMP file), skip straight to steps 3 and 4 to place them in the right folders.

Extract the zip

Right-click the .zip file and choose your extraction method. The options you see will depend on whether you're using Windows built-in extraction, 7-Zip or WinRAR:

Extract To "zip folder name": Creates a new folder with the same name as the zip file and places all the contents inside it. This is the tidiest option as everything stays contained in one place. Open that folder to find your mod files.

Extract Files: Opens a dialogue letting you choose exactly where the extracted files are placed. Use this if you want to send them straight to a specific folder you've already set up. Navigate to your destination and confirm the files have extracted properly.

Extract Here: Extracts everything directly into the same folder where the zip file currently sits, following the same folder structure that's inside the zip. If the zip contained a subfolder, that subfolder will appear in the current location. Best used when the zip contains only the mod files with no extra wrapper folder.

Whichever method you use, make sure you can find the actual .iff, .FAR, .BMP or similar mod files before moving on.

Find your game folder

Steam: right-click game → Manage → Browse local files.

EA App: right-click → Manage → Open install folder.

Place the files

Always check for a readme first. Many mods include a readme (.txt) file that tells you exactly where to put things. If one is included, follow those instructions over anything else - some mods need to go into a specific folder to work correctly, and the readme will tell you which one.

If there is no readme, use the file type and mod description as your guide. The most common locations are:

Most mods (.iff/.FAR) → Downloads\
Custom objects, furniture, buyable items and most gameplay tweaks go here. This is the default destination for the majority of mods.

Everyday skin files (.BMP/.CMX/.SKN) with prefix B or C → GameData\Skins\
Everyday body outfits (prefix B) and head textures (prefix C) go here. Must go directly in this folder - no subfolders or the game won't read them. These appear in your Sim's home dresser.

Buyable skin files with prefix L, F, S, W or H → ExpansionShared\SkinsBuy\
Hot Date introduced buyable clothing purchased from a clothing rack on a community lot - not found in the home dresser. These skins use specific first-letter prefixes: L = Lingerie/Sleepwear, F = Formal, S = Swimwear, W = Winterwear (Vacation), H = High Fashion (Superstar). These go in ExpansionShared\SkinsBuy\ rather than the regular Skins folder - no subfolders. See the Terminology page for the full prefix reference.

Wall coverings (.WLL) → GameData\Walls\
Subfolders are supported here if you want to organise by style or creator.

Floor tiles (.FLR) → GameData\Floors\
Subfolders are supported here too.

Roof textures → GameData\Roofs\
Must go directly in the folder - no subfolders.

Game file overrides (.iff) → GameData\Objects\
Mods that replace or modify an existing base game file rather than adding something new. For example, Corylea's Two Hour Carpool replaces the original carpool object to change when it arrives - because it's overriding a base game file rather than adding a new object, it needs to go in GameData\Objects\ rather than Downloads\. The readme will always specify this.

Expansion-specific overrides → ExpansionPack#\ (where # is 1-7)
Some mods target a specific expansion pack's files rather than the base game. These go in the relevant expansion folder. Again, the readme will tell you which number corresponds to which expansion.

Downloaded lots (.iff) → UserData\Houses\ (or UserData1\Houses\ etc. depending on which neighbourhood)
Lots are placed into the Houses folder for the neighbourhood you want them to appear in.

Launch the game and test

Start the game and check the mod is working. If something's wrong, see the Troubleshooting page.