Hidden trait

Hidden traits are traits in The Sims 3 that cannot be seen in-game except when a Sim performs a related action autonomously or an unlocked interaction is available.

Hidden traits become available to Sims in specific careers or to babies with an NPC for a parent. The child might then get the appropriate hidden trait.

Burglar

The Burglar hidden trait can be found in children of Sims in the Criminal career.

Burglars must perfect their sneaking skills to properly liberate imprisoned items from the homes of neighbors. Burglars like to keep the skill in the family, so their children are able to sneak out like a pro at birth.

• Can "Sneak" instead of walking or running.

Can Apprehend Burglar

The Can Apprehend Burglar hidden trait can be found in children of NPC Police Officers and Sims in the Law Enforcement career.

Police officers spend years learning how to best the most clever burglars. Luckily for their children, genetics helps them stop burglars without years of tedious training.

• Can fight NPC burglars on home lot.

Can Salute

The Can Salute hidden trait can be found in children of Sims in the Military career.

Children of high-ranking military officials know enough about the military's rules and regulations to snap off a smart salute when they want.

• Can "Salute" other Sims.

Immune to Fire

The Immune to Fire hidden trait can be found in children of NPC Firefighters or Sims in the Firefighter career

Fire Fighters are able to survive countless fires; not least because of their natural immunity to fire. It's a trait that they pass on to their children.

• Can not be killed by fire

Makes No Messes

The Makes No Messes hidden trait can be found in children of NPC Maids.

The descendants of maids have cleanliness imprinted on their genetic code so they never leave anything dirty.

• Never leaves messes, similar to an attribute of the Neat trait.

Pizza Appreciator

The Pizza Appreciator hidden trait can be found in children of NPC pizza deliverers.

Pizza delivery folks develop a love of pizza that's deeper than the thickest crust. Their children share a similar fanaticism for pizza, which makes every bite of hot pizza amazing.

• Eating pizza grants them the Amazing Meal moodlet.

Pyromaniac

The Pyromaniac hidden trait can be found in children of NPC Firefighters or Sims in the Firefighter career

You can only get this trait in a Sim who is the offspring of a firefighter Sim. The trait allows them to set fire to objects of their choice, and they get positive moodlets for doing so!

• Can transmogrify any fruit and turn it into a flame fruit.
• Can shortly set things on fire without destroying anything.

Rocker

The Rocker hidden trait can be found in children of Sims in the music career.

Sims with this trait will get a natural feeling of rock stardom.

• Sims with this trait occasionally play air guitar. ^{[confirmation needed]}

PrivateEye

The PrivateEye trait is a hidden trait added with Ambitions

• What it does or how to get it is unknown, however, it is guessed that it is gotten by reaching a certain level in the Investigator profession or maybe it is given to the child of someone in the Investigator profession.
• It has no icon.

Asian Culture

The Asian Culture hidden trait can be found in children of Sims from Shang Simla

The three "culture" hidden traits from The Sims 3: World Adventures have no in-game icons or descriptions.

• Chinese-themed idle animations.
• Uses chopsticks when eating.
• Sings Chinese songs autonomously.

Egyptian Culture

The Egyptian Culture hidden trait can be found in children of Sims from Al Simhara

The three "culture" hidden traits from The Sims 3: World Adventures have no in-game icons or descriptions.

• Sings Middle Eastern songs autonomously.
• Egyptian-themed idle animations

French Culture

The French Culture hidden trait can be found in children of Sims from Champs Les Sims

The three "culture" hidden traits from The Sims 3: World Adventures have no in-game icons or descriptions.

• Greets other Sims with a dual-cheek kiss (known in real-life France as La bise)
• Sings French songs autonomously.
• Gets a discount when visiting France.

Mummy

The Mummy hidden trait can be found in Sims who are mummies.

• Makes Sim behave like a Mummy

SimBot

The SimBot hidden trait can be found in Sims who are SimBots.

• Makes Sim behave like a SimBot.
• Cannot enter water
• Able to destroy household objects, like fridges
• Eat scrap instead of food
• Don't have a hygiene or bladder needs
• Able to get jobs, and have romantic relationships

Vampire

The Vampire hidden trait can be found in Sims who are Vampires.

• Makes Sim behave like a Vampire.
• Runs faster
• More interactions with Sims
• Secret trait is passed on to their children
• Brighter eyes
• Sharper teeth
• Gives normal Sims who don't know them a negative moodlet
• Night gives them a major energy boost

Sleeps in an alter