So, lately I've been having fun simulating an alien invasion in a town, and I've discovered by experimenting a few things about the special "pregnancies" and cheaty ways to add a few aliens in a town, including in inactive households. I thought it would be interesting to share !
The tutorials require Master Controller installed with the Cheats module. You can uninstall the mods after you've finished if you wish, as these households are fully functional and can be exported and uploaded to the exchange without any mods.
I've noticed that pregnancies from abductions aren't coded as "real" pregnancies, they're just a moodlet. If the abducted sim is male and his life state is human, there's a chance that "unexpected weight gain" replaces the "abducted" moodlet. It's the "abducted" moodlet that is responsible for generating "unexpected weight gain", not the abduction itself. Save your game just before the "abducted" moodlet ends and if you get or don't get "unexpected weight gain" and aren't happy about it, reload, because the result will be different every time the "abducted" moodlet ends.
As these "pregnancies" aren't coded as pregnancies, there's no way to influence the baby's gender, no matter how many watermelons or apples your sim eats, it's useless. So if you want a boy or a girl, save a few minutes before the pregnancy ends, and reload as many times as necessary. I've also been able to choose only one trait for the baby, but the other trait doesn't have a high chance to be bad contrary to unhappy pregnancies.
If you choose to raise the alien baby, what happens is that the game seems to generate the clone of a female alien in your town file (generally not the alien who abducted the sim). The clone can be male or female, and the female alien is shown as the baby's mother in the family tree. The mother appears in the baby's and father's relationship panel as an acquaintance with a completely neutral relationship. Just after birth, the father and the baby are friends immediately.
It's possible to induce the same type of "pregnancy" in inactive households. Choose a human male neighbour (young adult or older), and click NRaas -> MasterController -> Intermediate -> Moodlets -> Add moodlet -> Unexpected weight gain. Wait until the moodlet ends and voilą !
Once it's done, check that the "unexpected weight gain" moodlet is gone, by checking the sim's personal moodlets here : NRaas -> MasterController -> Intermediate -> Moodlets -> Remove moodlet. Remove "unexpected weight gain" if ever it's still present, and reset the sim in that case.
I've noticed that if these babies share their father's last name, the game gives them an alien first name.
The babies have 0 remaining days before age transition, so as their birthday can "get stuck" (it happened in my game a few times with any type of baby), I prefer to trigger age transition manually, just in case. They aren't more glitchy than other babies anyway.
Creating a custom alien household with CAS and MasterController + MasterController Cheats :Click on your town hall : NRaas -> MasterController -> Sims -> Advanced -> Edit in CAS -> Check without selecting any criteria and you can access your whole town's sims' list. If your town file isn't new, there must be several aliens in the list. Choose any you want and edit him / her in CAS. Save him / her to your library and quit CAS without saving. Now, you can create a household with one or more sim(s) who look like aliens, but only have the physical appearance. To give them spacesuits, use the following cheat :
unlockoutfits on . Save the household to your library. Make the household move in and start live mode. The sim(s) should look like aliens but will have "human" eyes and voice and have no powers. To give them powers, click the sim(s) in live mode -> NRaas -> MasterController -> Intermediate -> Alien DNA percentage -> Enter 100 for pure aliens, 50 for half aliens, or less depending on their level of hybridization with humans. Go back to main menu (don't forget to save). Reload. If it worked, your sims should now have black eyes, echo in their voice and powers. You can also check their status (their species should be listed as "Extra-terrestrial") in MasterController if you wish. You can save the household to your library and export it : your sims will now retain their alien status.
You can also make alien sims passing as humans by giving ordinary sims alien DNA. They will have powers, black eyes and echo in their voice, but will look human otherwise, although they aren't actually human. They also can wear a spacesuit.
First generation is Astra whose father is human and other parent is alien.
I was unable to hear her voice as a baby, toddler and child. When she turned teen I could hear her voice and the brain power bar showed up.
I've noticed this problem which is due to the fact that babies and toddlers can have only one voice, children can choose between two different voices and teens and older between 3 different voices in CAS. For babies, toddlers and children who have the voice number two or three, the file is naturally missing, so you can't hear them. They can be edited in CAS and assigned to voice number 1 for babies and toddlers, or voice number 1 or 2 for children. The issue will be fixed immediately like this.
