So Quatchi and I decided to set aside today to try to look into this issue. I just want to set expectations. This would probably be a fairly easy fix if we had the source code. It may be impossible without the source code. Even if we manage to get something working, it will only be for one patch level of one EP. Neither of us is considering anything else.

Wish us luck!

Good Luck Quatchi
Good Luck Mootilda

As in like AL or Uni or what? Shouldn't you consider M&G? Because, as mentioned before, its "the only SP that acts like an EP"(?).

And BTW, good luck!

M&G. I've been avoiding the Store Edition.

Quatchi said something that I thought was really funny: "EA won't fix the bug because they think that you caused the bug by modding the game to avoid generating tons of random townies." I had never really considered the idea that EA doesn't believe that the bug exists. But, if their testers work without mods (expected), then they would probably never see this bug. Pescado caused it when he wrote notownieregen!

[Update:]

Things went fairly well yesterday. We verified that a 1-byte change to the active data will resolve the problems with both genetics and personality (haven't looked into names yet). Then we were stymied for the evening, but I had one of those middle-of-the-night inspirations so I think that we're back on track. We just need to find some more time to get together and work on this again. I am still hopeful that we'll be able to get something with proper randomization.

I know this thread hasn't had a reply in 2 years, but I needed to ask some dumbo questions, if anyone is willing to help.

1. Has this been solved in a patch or an EP? If it has, disregard the rest of the questions! :P

2. (This is a really dumbo question, ogay) Does this "First Born Effect" apply to every subsequent children in one family, or the rest of the neighborhood couple's offsprings?
To better explain myself: I load my first family, a couple. The female gives birth, and I save the lot and exit. Now I want to go ahead and play another couple family who is going to have a baby born, do I have to "roll the pacifier" again? If I do not do so I'm pretty sure this baby in household 2 won't look exactly the same as the baby in household 1 right? The parents do have different genetics afterall, but asking this just in case :P

3. They said you would have to reroll the pacifier every time you start the game to prevent the First Born Syndrome.
Does it mean by: a) every time you open your "The Sims 2" or b) every time you switch households?

4. Relating to Question #3. If Family #1 in my hood has a baby, then I save and go to the neighborhood to play Family #2, and they have a baby. I want to go back to Family #1 and have another baby, do I have to roll the pacifier again? They said the game generates the same genetics each time you start the game, will it go back to square one if you switch households?

5. Does the First Born Effect only apply to personality points, or the face as well?

Before anyone asks me to read the Pregnancy Guide, I already did. It was quite hard to wrap my head around it. (It was pretty confusing, but I do understand most of the First Born Effect concept, I just need some clarifications.)
If you answer them, thanks

1. Nope.
2, 3, 4. It applies to the first child born during a single load of the game. If a baby is born in one house, and you then move on to another house, in which another baby is born, the second baby will not need the pacifier rolled regardless of whether you rolled it for the first one or not. If you make sims in CAS, and use the pacifier button to make a child, or even use the dice to randomize premades, you will not need to roll the pacifier specifically for any family that may produce a baby during that play session.
Every time you open The Sims2 (and expect to have a baby).

What happens is that the random number generator in charge of genetics has a built-in flaw that causes it to reset to the same starting point every time you load up the game. Once you grasp that, the rest will be easy to remember.

5. If you read backwards through this thread, you will find that, though at first it appeared to only affect personality points, many people only become aware of it due to sim siblings looking like each other. Extensive testing indicates that both are affected.

As far as I can tell, the same randomizer also applies to pets at pet births and the random generation of a new pet for those occasions when the game decides that a sim has bought a pet while in the background of somebody else's community lot visit; and if this is the case, then you shouldn't have to roll the paciifier if either of those events happens before a birth. I took a chance on that this week, and it seems to have worked. But I can't remember whether I rolled the pacifier for the first birth in this family, so the fact that I have no clones doesn't truly prove anything. This assertion should be tested before you start spreading it around as gospel.

It also applies at pet births? Does that mean that you have to roll the pacifier before pet births or your puppies/kittens will all be identical?

I am making a logical extrapolation; I do not know this for a fact. It's less of a problem with pets in any case.

This thread may be older than dirt, but people still need to know this stuff. And I do have dirt in my house which is much, much older.

Old thread so please redirect me if there is a newer one - but i'm having an issue where rolling the pacifier with the batbox and with CAS suddenly stopped being effective. I tried to read through the thread to see if there are any ways to fix it but I'm a new sims 2 player and I didn't understand a lot of it.

Amiisay, how do you know it's not working? I ask mostly because I use the batbox method and I just always trust that it does work; I've never been much good at actually seeing/noticing the syndrome myself, so I don't know if I'd ever notice that it had stopped working.

Have you checked and made notes of the personality of the sims born in game? They should be different if you're randomizing with the Batbox or in CAS. Keep in mind, if the parents have the same face template, or if they look very similar, the children may not have much variety in looks, no matter how much randomizing you do. But randomizing should prevent identical personalities in siblings. If it's not, there's something wrong somewhere.

The batbox's randomizer is not perfect either. Mootilda was still working on fixing that when she died.

The way the batbox works in this case is, it rolls a random number of CAS sims and discards them without saving, all at once - i.e., doing the same thing you do, only much faster. If the randomizer malfunctions consistently, though, it may always be rolling the same number of CAS sims, which merely shifts your firstborn syndrome to a different point in the progression. When Mootilda opened the game and used the batbox randomizer first thing, she always got 13. (The batbox will give you a pop-up telling you how many "items" - i.e. CAS sims - it made and discarded, so you can easily test whether this is what's going on.) When I use the batbox in normal play, however, I will get numbers anywhere from 2 to several thousand, so my playstyle is doing something that cancels out the randomizer problem.

If this is your problem, you could either use the batbox a random number of times (if you're always using it the same number of times the problem will recur), or go into CAS and use some other random number method to determine how many times you roll the dice. You don't have to go through the whole process of rolling the actual pacifer - rolling the dice in the CAS screen a random number of times will do it. I'm a tabletop gamer so I always have polyhedral dice on hand; other people like online randomizers, or you can just sit there clicking till you get a sim you like or your finger gets tired. The important thing is for the game randomizer to be used a different number of times each time.

Remember also that the pacifier must be rolled during the game session of the birth, before the birth takes place, since sim genetics are determined at the time of birth. Rolling it during pregnancy won't help if you quit the game before the birth occurs.

I know this post is old, but I did make a curious observation a while ago. Some of my playable Sims purchased pets (and yes, I know there are hacks to disable this; I like it, though). The pets themselves changed if I exited without saving and then reloaded the lot (only when the initial prompt comes up). But unless I rolled the pacifier, though, the personalities would always be identical - Aries 1/2/3/1/2 in my case.

The thing with pet births though is that they have more than one at a time. On the rare times I let them breed they pop out identical puppies (or kittens). It's easy enough to change their looks but it's still annoying. I don't see how the pacifier helps.

I'd think it's still affected by the faulty RNG, though.

Multiples shouldn't ever be identical - they should move down the progression with each birth. That's how multiple births work in human sims. The only multiple pet birth I've had was the Critturs, and they're all different. (Though, to be fair, they haven't grown up yet and I could be in for a shock, I suppose.) If you're just using the standard breeds there's less genetic variety in pets than in human sims, so perhaps that's what's causing this effect?

Clearly, systematic testing of pet birth randomization is needed.

Wait, how do you get the Batbox to give a pop up? It's never done that for me. My pet births are non identical. Though puppies and kittens often look identical until they age up, just like Sim babies.

Save your lot, click on the Batbox and choose "randomize sim generator" (I think that's what it's called; it's something very like that). I don't remember what menu it's under, but it might be "fix"? I don't generally have any trouble finding it. It will pop up with a message warning you that it will exit the lot without saving and that the game will freeze for a bit and ask if you really want to do it. Click "yes" if you are in fact sure you're ready. Wait a few seconds as the Batbox does what it needs to do, and then another popup will tell you how many places it advanced the generator. Click "okay" and you'll be booted to the neighbourhood screen. After that, go back in and play to the end of the pregnancy.

I know how to use the rerandomiser - it's just never ever given me a pop up. I get the screen saying that it will quit without saving, but then it just hangs and quits to neighbourhood. I assumed that it was working because it did that. Do you have to have testingcheats on? It does seem to work to randomise my births but I'd be interested to see what the number is.

My version of FFS Debugger was modified 1 September, 2009 at 18:00 and is 61.3kb. Perhaps I have a different version?
Edit: Curiouser and curiouser! I just grabbed one from the site, and the file was last modified in 2012. I must have had some version pre 2.0 for some reason! I will update you next time I play.

No, I never have testingcheats on when I use it.

Edit:

Mine's from 2012 as well. Hope that version works properly when you try it!

Since there is some uncertainty regarding the firstborn syndrome in pets, I would like make an interjection. From my personal experience, I do believe pets are also affected by the firstborn syndrome. I often breed my animals in game as I like for my sims families to pass down the same bloodline of pets through the generations. I have found that if I don't take anti-first born measures before the kittens or puppies of a second or further litter from the same two parents are born, they often will be identical in appearance and personality to siblings from previous litters.
I first observed the affect while attempting a legacy challenge. The aim of the particular legacy was to keep the same blood line of pets within the legacy family for the entire ten generations. After my first gen pet hair(a flame point Siamese) had her first litter I fully quite the game. The next real-life day I loaded the household back up and immediately got her pregnant by the same male using the reproductive adjuster and forced the delivery. Upon growing up the two kittens from her first pregnancy where very different from each other. On the other hand the single kitten from the second litter had the exact same personality, markings and coloration as the older kitten from the first litter. You can see it in this post here. The first litter grows up near the beginning while the younger one grows up toward the end of the post.
Since then I have encountered the same thing with other pet births as well. I should note that at the time I did know of the first born syndrome but didn't bother to actively counteract it. It was largely the effect of this family that caused me to start as I believe that some of the sim children were affected as well.
Probably the effect of the first born syndrome on pets isn't as noticeable as on sims for a few reasons...
1. As some one else on the thread pointed out, pets have more multiples then human sims ,so each puppy/kitten in a litter can be very different from each other.
2.It seems to me few Simmers breed their pets as often as they breed their actual sims so there is less references to go by with regards to the "bug's" effect on pet offspring.
3.Perhps those who do breed pets more often, are less likely to breed the same two pets multiple times, then breeding one pet with a different mate each time.
As for prevention, all I can say is that once I started using the anti-first born measures to prevent it in my sim babies I saw a decrease in it with kittens and puppies as well. I can't really attest to the effectiveness of any one typical method however as its been so long since I used any given one. Since my personal anti-first born routine is essentially a manual version of the batbox method I can say that the batbox likely works for pets as well. I can't confirm whether or not the CAS method works. I will test around with the cats in my current household to see the extent of the effect on pets.

The batbox method is exactly the same as the CAS method, Keyqueen; it's just automated and doesn't require CAS to be open.

Ok, I wasn't sure. I didn't know why they would be different but I assumed they were because, at least in my game the batbox seemed to be more effective. I have never had the batbox fail where as I did end up with the first born syndrome on a very few occasions despite being sure I had used the CAS method. Of course its always possible that my memory was faulty or I had rolled the pacifier the same number of times without realizing it.

That is entirely possible.

I've heard that the batbox sometimes manages to roll the same number as well... :/

Yeah, Mootilda was still looking into that when she died. When she opened a neighborhood and rolled first thing, she always got a 13, evidence that the randomizer Pescado used wasn't much (any?) better than the one in the game. (I believe this is discussed upthread but I'm too tired to go look.) But every time I roll it I get a different number - as far as I can tell given that I never remember numbers - but I know I've gotten anywhere from single digits to four in that pop-up telling you how many CAS sims were created and discarded. So some playstyles are adequate to offset the problem with the batbox randomizer.

Other people, who presumably like the way they're playing now, would be well-advised to use their own random number generator (a set of dice will do) to roll the pacifier in CAS or with the batbox a random number of times, until someone fixes the batbox.

If you forget to roll the pacifier before a birth, the tradition is to quit to neighborhood without saving and enter the lot again. This will only get you moved one along in the "random" sequence, though. So quitting to neighborhood, rolling the pacifier, and then letting the birth happen is a wiser choice. And of course, if you're insisting on a particular gender and keep trying till you get it, that'll randomize the genes all by itself.