Hidden traits cannot be seen ingame except when a Sim performs the related action. They can only be acquired through genetics without mods. You can get these traits by having a baby with certain NPCs or a sim in a specific career. Your child will then get the appropriate hidden trait.
BurglarBurglars 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.
- From NPC burglars and Sims in the Criminal career. [confirmation needed]
- Can "Sneak" instead of walking or running.
Can Apprehend Burglar
- From NPC Police Officers and Sims in the Law Enforcement career.
- From Sims in the Military career.
- Can "Salute" other Sims.
Immune to Fire
Makes No Messes
- Eating pizza grants them the Amazing Meal moodlet.
- From pizza deliverer.
Pyromaniacmoodlets for doing so!
- From NPC firefighters [TS3] and Sim firefighters at level 8+ of their career. [TS3:A] [confirmation needed]
- Can set fire to an apple and turn it into a flame fruit. [confirmation needed]
- The only premade sim who has this trait is George Dean.
- From Sims in the Music career.
- Sims with this trait occasionally play air guitar. [confirmation needed]
- From Sims in Shang Simla.
- Chinese-themed idle animations.
- Uses chopsticks when eating.
- Never get fatigued while practicing Martial Arts. [confirmation needed]
- From Sims in Al Simhara.
- Sing Middle Eastern songs autonomously.
- From Sims in Champs Les Sims.
- Sing French songs autonomously.
- Greets other sims with a dual-cheek kiss.