Burglar

A burglar is a Sim (an NPC in The Sims,The Sims 2 and The Sims 3), who will sneak onto a lot when all Sims are sleeping, or off the lot for some reason, most often during the night, and attempt to steal items from the household. The burglar in The Sims was male, and known only as "Some Sneaky Sim." In The Sims 2 and The Sims 3, burglars can be either male or female. Burglars can steal possessions of any size, and will often steal the most valuable items on the lot. Burglars can be arrested by the police if they are summoned quickly enough - the only way to ensure that the police are called in time is to install burglar alarms. If the lot doesn't have an alarm, Sims can call the police, but the police may not arrive in time to stop the burglar from escaping with the Sim's possessions, so it's always a good idea to buy alarms as soon as possible. In all games, it is impossible to enter build mode or buy mode after a burglar enters the lot.

The Sims
In The Sims, burglaries are very rare and will most likely appear only if the selected family is wealthy and/or has expensive objects in their home. However, families with little money may also be robbed. The burglar will usually appear at around 3:00AM, and his arrival will be announced by a few bars of intentionally frightening music. The burglar cannot be interacted with in any way, except by the police, and was specifically designed to rob houses while the entire household is asleep. If the player tries to wake up a Sim while there is a burglar, it is unlikely that the Sim will wake up, get to a phone, and call the police in time to catch him. Even if the player does this as soon as the burglar appears, it is not certain that the Sim will be able to call the police in time to catch the burglar. This is most likely because the game has programmed burglars to only appear when a Sim is asleep. This can further be proven during rare occasions when a Sim is awake while one arrives on the lot they cannot stop the burglar as there are no available interactions and they will not react to one at all.

Burglars will steal the closest and most expensive objects they can find. Installing a burglar alarm in the home will not prevent a burglar from entering the lot, however if one happens to do so, the police will arrive and take him away. The police officer will thank the family and will give them a small amount of money for assisting the law. Despite this, the burglar may have already taken one or two items by the time the police officer approaches him. These items will be kept as evidence, and not returned, but the family will be reimbursed for them. Sometimes, a family will be reimbursed for an item that the burglar did not manage to steal.

The Sims 2
In The Sims 2, a burglar who enters a lot will "case" the house and lot, looking for the most expensive items. A burglar can steal aspiration reward objects, and will consider the number of aspiration reward points needed to buy the reward as its value.

If the burglar trips an alarm, this may give the police time to respond before the burglar can steal anything. Unlike in The Sims, Sims will panic when they witness a burglar entering a lot. They can use a phone to call the police, but cannot interact with the burglar. All Sims on the lot will also have the "Burglar!" memory, even if the burglar is captured.

Some Sims, particularly Fortune Sims, often have "getting something stolen" as a fear. If someone in the household encounters the Burglar, they will often react with fright. When/if the police arrive, the officer will attempt to apprehend the burglar by fighting him/her; if successful, the burglar will surrender, but if the officer is defeated, the burglar will escape. If the police officer and the burglar cannot get into a position that allows them to fight, the burglar will flee.

With The Sims 2: Open for Business, Sims with a Silver or Gold Robotics Badge can use the Robot Crafting Station to craft SentryBots, which are designed to patrol a house and electrocute (stunning, not killing) any burglars that may enter until the police can arrive.

Something that is useful to have in mind is that, on rare occasions, the player can immediately go to buy mode or build mode if the burglar has just entered the lot and the game has not picked up on it. This can be very helpful if it can be managed, but it is not something that should be counted on. In most games, there will be a little pause right before the burglar arrives. This can also help determine when the burglar is about to arrive.

NPC burglars may appear on community lots, and in The Sims 2: Open for Business, may visit an owned business. While they will likely be dressed as burglars, they may be there to shop, not steal.

Tips

 * If a house has a back door, a burglar may enter through it.
 * A car with an alarm installed can serve as an outdoor alarm. It will go off if a burglar comes within range of it, even if the burglar doesn't walk past the car. Since a car will often be one of the more expensive objects on a lot, a burglar may come within range of the alarm as they "case" the lot. When the car alarm goes off, it will not wake Sims sleeping in the house. Alarms in the house will not sound, even if the burglar enters the house.
 * Beginning with The Sims 2: Nightlife, after a burglar has entered the lot, the burglar will appear the Relationships panel for Sims in the family. They will all be furious with the burglar, though they will not become enemies. As with other Sims in the Relationships panel, it is possible to call the burglar on the phone and raise the relationship.
 * A SentryBot will shock a burglar.
 * Werewolves can fight the burglar like a cop. They will always win.
 * Bigfoot will immediately scare the burglar away. If the burglar's bladder level is low, he/she will experience bladder failure.
 * The butler will immediately call the police whenever a burglar is seen.
 * The range of a burglar alarm in The Sims 2 is one "room", and the alarm may not be placed outdoors. An alarm may be moved outside by constructing a small room surounded by walls, placing the alarm inside it, and then demolishing all its walls except the one that the alarm is attached to, or by using the moveobjects cheat. The alarm will then cover the entire outdoor area, only limited by any fences.
 * Burglars also appear in College sub-neigborhoods. On rented residential lots not dormitories though.

The Sims 3
In The Sims 3, burglars can be interacted with, which was not possible in previous games, but the options are very limited. Sims now have the power to stop them if they have the Brave trait, which gives them the option to "Fight" against the burglar. Winning against the burglar will chase them away but will not help return items that have already been stolen. Also, a pet with the aggressive trait can chase the burglar away. If the police were called, they may reward the Sim with some money for helping them catch the burglar.

However, when the police are called, the burglar will not be immediately caught. When the police arrive on the lot, the burglar will stop whatever he/she is doing and will engage in a fight with the police. If the police wins, the burglar is arrested, otherwise the burglar will escape with any items he/she has stolen.

Playable Sims can also become burglars if they choose to become a thief through the Criminal career track, though this does not allow them to rob other houses. However, it is possible for any Sim, regardless of career track, to steal items if they have the Kleptomaniac trait. That trait allows a Sim to take 3 items from a residential or community lot that he/she is visiting at night.

It is also possible to befriend burglars and turn them into playable Sims by becoming acquainted with them. One possible way to do this is for a Sim to help them escape after being handcuffed by the police. Usually after making an arrest, police will tell the burglar to wait outside the police car while they check around the house. During this time, an option called "Set Free" will be available if the burglar is clicked on. Another way is through the "Fight" interaction also available to Sims with the Brave trait. Afterwards, the burglar will become acquainted with the Sim allowing the player to call the burglar to have a chat or invite over to their house during the day when they are not working as burglars. They can then ask them to move or marry into the household once they have built enough relationship points. Burglars who have become playable Sims possess a hidden trait called 'Burglar' which gives them the special interaction to 'Sneak' when moving. Children who are descended from Burglars can inherit this trait.

There are many ways to counter a burglar in The Sims 3:
 * Call the police.
 * Install a burglar alarm.
 * Have the Brave trait and fight the burglar yourself.
 * Have the Can Apprehend Burglar hidden trait.
 * Have the Light Sleeper trait as they will immediately wake up and call the police.
 * Have a pet with either Aggressive or Loyal trait can help scare the burglar away.
 * Lucky Sims with "Feeling Lucky" moodlet will not be visited by burglar for sure, unless they don't have that moodlet.

Player notes

 * Using  cheat will allow players to enter the Build / Buy Modes when a burglar or fire is on the lot.
 * Home owners can set the burglar free while the police are inspecting the house. Afterward, the cop will give the Sim a stern warning to not set burglars free.
 * There is a hidden trait called Burglar. This gives Sims access to the 'Sneak' interaction.
 * They can also rob vacation houses on The Sims 3: World Adventures locations.
 * Burglars will freak out when the alarm goes off.
 * Burglars will immediately retreat at the sight of a mummy in World Adventures.
 * Having a Sim with Good or Coward trait makes Can Apprehend Burglar hidden trait and Brave trait useless.
 * Burglars will almost always attempt to rob houses without burglar alarms.
 * Houses that are very large, luxurious, and have expensive goods are more likely to be robbed.
 * Scary music will play when a burglar appears on a home lot, alerting the player.
 * Burglars can appear when no sims are home, but it is very rare.
 * The burglar may enter through a back door, if there is one.
 * Neighbor Sims can come and help the Sim fend off the burglar (ex. Erin Kennedy).