A downloadable mod

NOVEMBER 2018: New update for Sims 4 patch Newborns and adoptees are now affected, though the magic won't work on adoptees until they're brought home.

A quick and dirty mod that randomly applies custom gender traits to NPCs who haven't already had the defaults applied to them. Most (all?) premade sims in a new game and any new townies should be eligible.

What happens, exactly?

Ordinarily, when a sim is loaded during gameplay, they are given a set of gender traits (masculine frame for males, feminine frame for females, etc.) if none have already been assigned to them. This mod allows the game to vary those traits. A male sim might be able to get pregnant, a female sim might prefer masculine clothing.


idk why not


Place cosmic_gender_ray.ts4script and cosmic_gender_ray_settings.json in your mods folder. They should both go in the same subfolder, or in the root of the mods folder.

The included .json file isn't strictly required, but I recommend you customise its values to your liking before running the game with this mod. A new file with default values will be generated if it's missing or invalid.

You must have script mods enabled for this to run.


Editing cosmic_gender_ray_settings.json allows you to adjust the probability a trait will be picked for male and female sims. There's no in-game settings menu, sorry!

As an example, under female_sim:


      "wear_feminine": 80, 
      "wear_masculine": 20

will give most (but not all) female sims a feminine clothing preference.

If you're unsure your syntax is correct, you can run the contents of your file through JSONLint.


  • Changes won't be applied to premade sims until you play a household
  • Clothing preferences applied by this mod won't be reflected in a sim's existing outfits
  • I've no idea how the game handles a sim who can both impregnate and be impregnated
  • It's possible to have the script assign additional traits by editing the settings if you're daring enough and know your hashes

Thanks to scripthoge for that injector thing everyone uses and to scumbumbo for including source with SCAM so I could have an example of how to do things


cosmic_gender_ray_v2.zip ( and later) 5 kB
cosmic_gender_ray.zip 4 kB


Log in with itch.io to leave a comment.

Does this mod need to be updated since the big infants patch? Thank you. This is one of the most important mods I play with.

(1 edit)

i haven't played ts4 in a while so i'm not sure, sorry! the mod seems to have been pretty patch-resistant in the time since i last updated it, so hopefully it's still okay.