The Sims 4 features some hidden traits that are never visible.

If using a mod and selecting the Rocker trait in Create A Sim, an animation will be played, unlike the other hidden traits.

Using 3rd party mods or cheats to simply add the hidden traits for various occults does not properly apply occult status and will cause problems, unless the trait is 'PlantSim'.

Sims can get the unicorn trait by using a 3rd party mod.

They will get the 'Singed' moodlet, but they won't die if they catch fire again.

Even though a Sim has the immune to fire hidden trait, they can still be caught on fire from inventing, making metal sculpture, taking an experimental treatment from the Science career, or from a fire trap.

With the secret can apprehend burglar trait, if the Sim has the coward or good trait, they are unwilling to fight burglars.

The ability to sneak with the secret private eye trait is only available for young adults and older.

If a Sim has the good trait and the secret private eye trait, the Sim won't have the option to beat up other Sims for information.

Despite the fact that pyromaniac's fire does not harm anything, it will still trigger the fire alarms if there are any nearby, summoning the firefighter and leading to a fine.

If a Sim in a house has already bought the Fireproof Homestead lifetime reward, a pyromaniac Sim will not be able to set a fire on that house.

Hidden traits sims 3