Running away is an event found in The Sims series, first introduced in The Sims 2. Originally, it was centered around teen Sims, who may depart the household as a protest against negative relationships. In later installments, the feature more commonly affected pets, who may run away due to neglect or low mood.

The Sims 2

A teen Sim can run away from the household in The Sims 2, when the particular teen has negative relationships with the other members of the household, and has few or no other friends. When a teen is preparing to leave, a message will pop up in the upper-right hand corner letting the player know. Then, the teen either walks or runs off of the lot. The memory associated with a teen running away is usually red, but may also be green depending on the Sim and their relationship with the teen. While running away, a runaway icon will appear on their picture. Being gone does not affect things like school grades.

If a player wants the teen to return as soon as possible, the parents of the teen must report the runaway via telephone to the police. Doing this will increase chances of the runaway being returned by the police. If the teen is reported after twenty-four hours, the chances of being returned by the police decrease to about fifty-percent. If the teen is returned by the police, they will not run away again for more than twenty-four hours. If nothing is done about the run away, the teen will return home one day before they Grow up, and will not run away again.

With The Sims 2: Pets installed, pets can also run away. They may run away due to a number of circumstances, including:

• Having a low relationship with all other Sims/Pets on the lot.
• Witnessing a fire.
• Losing a fight with another pet.
• Their motives are too low.
• A Sim who they see as their Master dies.
• Etc.

Getting a runaway pet back follows the same steps as with teens. A unique memory will be added to the memories of other Sims upon running away, and another when the pet returns. If the pet has a collar, there is a chance that the pet will be found and returned even if it was not reported as having run away. If a pet without a collar is not reported missing, after several days it will be removed from the household and become a stray, though it can be adopted again if it visits the household. This also happens if a pet is found but the player refuses to take it back.

If playing another household, a runaway pet may appear on the lot, and if it has a collar or its owner is known to the household the owner can be called to pick up their pet, with a possibility of a monetary reward. The runaway can also instead be adopted if it's friendly with someone in the household, regardless of whether or not the owner can be contacted.

The same behavior for pets can also be found in The Sims 2: Pets (console), however, as there are no teens, Sims themselves cannot run away.

The Sims 3: Pets

In The Sims 3: Pets, pets will run away if a fire breaks loose, if their relationships with the household Sims are low, or if their mood is too low. Lost pets leave a bad moodlet that lasts until the pet is found. Sims may find their pets wandering around town, and their moodlets can indicate where they are. For example, when a pet is at the library, the moodlet associated with libraries will be present.

Running away returns in The Sims 3: Pets for console. Pets will often run away if they become startled, such as when they are near a fire or a detonated object. When a pet runs away, a notification will appear informing the household of the event. Their portrait will display a red exclamation point, and the pet will temporarily become unselectable; when hovering over their name, the text will appear in red, reading "(Pet Name) is lost!" Although they cannot be selected, their moodlets and motives can be viewed in the menu. Their motives are fixed to be around 20% full until they are found.

Sims can report the disappearance to authorities on their cell phones. To find the lost pet, Sims must search around the neighborhood, as a pet can be anywhere on the map and not necessarily on a lot (for example, sitting behind the city hall). Once the pet is located, they will become selectable again and all their motives will automatically be filled.

Icon	Name	Effect	Cause	Description	Notes	EP
	Lost Pet	-25 Mood	Pet Running Away	Oh, no! You have a pet that has gone missing! You can use the cellphone to report them as lost and hopefully someone will find them for you. You might also get lucky and find them wandering around town... somewhere.	Lasts until pet is located.

The Sims 4: Cats & Dogs

In The Sims 4: Cats & Dogs, pets may run away, especially those with the free spirit and adventurous traits. They may also run away if they have low relationships with others in the household, get into a fight with other pets, or have a low affection need. Sims can post an alert using a phone or computer to speed up their return, and all Sims in the household will get a 2+ sad moodlet for the duration of the lost pet. The pet will return within a few days, sometimes with an object or an illness. Pets with the prowler or hunter traits are more likely to return with an object. If they have not been spayed, there is a chance they return home pregnant.