How to Edit Pre-Existing Sim Relationships in The Sims 4

Changing the relationship status between two Sims who already exist in your game — whether they're strangers, old enemies, or a family you've played for hours — is one of the more practical things you'll want to know how to do. The Sims 4 doesn't make this obvious through its standard menus, so most players turn to a combination of in-game cheats, the Manage Households tool, and third-party mods depending on what they actually need to change.

Here's a breakdown of how each method works and when it applies.

What "Relationship" Actually Covers in Sims 4

Before diving into the how, it's worth understanding what the game tracks. Sims 4 manages relationships across two separate layers:

• Relationship type — the formal label: romantic partner, best friend, enemy, sibling, parent/child, etc.
• Relationship scores — two numeric values (Friendship and Romance) that run from -100 to +100 and drive most social interactions and autonomy

These aren't always in sync. A Sim can have a high friendship score with someone they're not formally labeled as friends with, or carry a romantic label without a strong romance score. Editing relationships properly often means addressing both layers.

Method 1: Using the Relationship Cheat (MCCC or Base Game Cheats)

The fastest way to adjust relationship scores on existing Sims is through the base game's built-in cheat console.

Steps:

1. Enable cheats by opening the cheat console (Ctrl + Shift + C on PC/Mac, or holding all four shoulder buttons on console)
2. Type testingcheats true and press Enter
3. Use the following cheat format:

modifyrelationship [YourSimFirstName] [YourSimLastName] [TargetSimFirstName] [TargetSimLastName] [value] [relationship type] 

Relationship type strings to use:

• LTR_Friendship_Main — adjusts the friendship score
• LTR_Romance_Main — adjusts the romance score

A value of +100 maxes out the relationship; -100 tanks it.

Example:

modifyrelationship James Smith Sara Jones 100 LTR_Friendship_Main 

This method works on any two Sims in the same save, including Sims in unplayed households. It does not change formal relationship labels like "husband," "sister," or "enemy" — just the underlying scores.

Method 2: Changing Family Relationships via CAS (Create-a-Sim)

To edit family labels — making two Sims officially siblings, parent/child, or spouses — you need to go through Create-a-Sim via Manage Households.

Steps:

1. Click the three-dot menu (or press Esc) and go to Manage Worlds
2. Find the household containing the Sims you want to edit
3. Click the household, then select Edit in CAS
4. In CAS, hover over a Sim's portrait and use the relationship assignment tools to define how they relate to each other

This is the cleanest way to set or correct family trees. It's particularly useful if you've moved Sims into the same household and want the game to formally recognize them as related.

⚠️ One important limitation: CAS relationship edits only apply within the same household. If the two Sims live in separate households, you'll need to move one temporarily, edit the relationship, then move them back — or use a mod.

Method 3: MC Command Center (MCCC) Mod 🎮

For players who want full control over relationship labels across households — including things like setting someone as an ex, a cousin, or an estranged parent — MC Command Center is the most comprehensive tool available.

MCCC adds an in-game menu (accessed by clicking a Sim or a computer) that lets you:

• Set formal relationship labels (romantic, family, friend, enemy) between any two Sims in the save
• Adjust relationship scores with more precision than console cheats
• Manage pregnancy flags, household structure, and more

Because MCCC is a third-party mod, it requires manual installation into the Sims 4 Mods folder and carries the usual caveats: it needs to be updated after major game patches, and using it adds a layer of complexity if you troubleshoot issues later.

Method 4: The Sims 4 Script Mods (Advanced) 🛠️

Some players use dedicated relationship-editing mods like Relationship Panel Overhaul or similar tools that surface relationship data more transparently and let you make changes through a cleaner UI. These are worth exploring if you're managing large legacy saves with complex family trees.

The tradeoff: more specialized mods are narrower in scope than MCCC but can be lighter-weight if you only need relationship editing.

Key Variables That Affect Which Method You Should Use

What You Can't Easily Change Without Mods

The base game cheats don't let you assign or remove specific family titles (like "sibling" or "parent") between Sims in different households, and CAS edits are household-scoped. If you're on console and can't use mods, your options are limited to score adjustments via cheats and any label changes you can make by merging and editing households temporarily in CAS.

The right approach depends entirely on whether you're fixing scores, labels, or both — and whether your Sims share a household or not. Those two factors narrow the decision considerably before any other preferences come into play.