So, I've tried to search the forums and the internet and nothing helps.

It's about the nannies. My question is, can you outright move a nanny into a household without screwing up the game? I've seen mods that allow for live-in nannies, but having them just move in without that is what I'm worried about. Is a nanny considered a safe NPC?

In Sims 2, we had a long list of what-not-to-do's and a list of safe and unsafe NPC's because let's face it, as great as it was, it was very finicky. So, now, I'm a bit paranoid of just doing simple things and such because I've had to reinstall Sims 2 and restart the entire game and years of progress at least a handful of times.

Is there a list of safe / unsafe NPC's and a list of what-not-to-do's that I'm not finding for Sims 4 that we had for Sims 2? Are there many restrictions? I have heard that Sims 4 is a bit more stable. Is that true?

I believe (at least, this is how I find it easy to do) to move ANY NPC into a household, they have to become a household themselves. Hence, mods are required.

MCC is a kind of master mod that even people who try to mod as little as possible use. You can click on your NPC nanny this way and add them to your family household using it. In terms of it breaking your game, from experience and what I've seen online to date, this is one of the few things that The Sims 4 is actually very stable in.

What the game will do is recognise that you've added the usual game-chosen nanny to a household, and it simply creates a new one instead. I've outright deleted ugly repairmen, mailmen, delivery men (and women to all of these) and the game will simply regenerate another one or choose another NPC from its pool.

A word of caution though - I've never tried this with nannies. But if they're anything like all the other NPC's I've deleted, you're in safe hands.

Hm... I did move them in without them being in a household so maybe I had a mod which helped me do this and I didn't realize it. Like the MCC or something. I was able to click on the nanny and add them into the household as xSwitch has mentioned. So, maybe I'm okay.

That's hilarious, and good to know. Thanks.

You won't "break the game" moving NPCs in to a home. The worst that will happen is they may lose their unique NPC job status and just become a regular sim. The game will then generate a new sim the next time that special job is called into service.

Each new service NPC is given a hidden trait binding them to that service role. On that hidden trait can be a single line of code which will determine if that sim is playable or not. If Maxis have decided they are not playable, then moving them into a home (as part of a family) will kill their special NPC job status. They will become normal sims and be replaced by another to take over their old job as and when needed. So, not really game breaking.

If that line of code is not added to their special hidden trait (or removed by a modder) then they can be made a playable member of a household and keep their special NPC job. Though in many cases will be difficult to play with as they may become increasingly unhappy about always missing work if their special job has been set up to be a 24/7 availability affair. Hence why Maxis would have flagged them not to be playable. And if you made the mistake of telling them to go to work to be happy again, then that sim will not ever be coming home again as that is the nature of their 24/7 job. All in all that particular workaholic sim not much fun to play.

The debug cheat to add sim to family is a base game cheat, MC only adds accessibility to it through its options, but the cheat can be utilized without MC being installed. A better option may be to use a more modern cheat to force unique worker NPC to become a roommate, - or not using cheat just become good friends and ask them to be roommate - where you do not make them playable so as to break their unique job status. However the same 24/7 going off to work and never coming home again rule will still be a thing.

The wonderful life of a unique worker NPC. And as far as nannies go, I do not know if they have the line of code in their hidden trait that would end their unique job if made playable. And even if they are fine with moving into a family and still keeping their unique job, while living with that family as another member of the household, they'll just be acting as a normal sim as their role to be an nanny (or any other unique job type) will not be active during that scenario. Although probably becoming more and more unhappy for missing work until you allow them to leave for work to which they will never return as most unique NPC jobs are open-ended, always on call 24/7 affairs. It would be best to then utilize another type of cheat to remove that hidden NPC worker trait and make them a normal "happy" sim, just let the game generate a new replacement sim for the role.

I tried the Live In Nanny mod by LMS but it was pretty much useless to me. Same with Live In Maid. After the maid finished cleaning the house, she'd spend the day compulsively cleaning the BBQ over and over (even though it wasnt dirty), making it actually unusable. The Nanny was hit-and-miss with getting it right. Might hire a butler to see if it's any better...

That's like Hank Hill's dream nanny.

... Propane.