Can someone please explain me in the simplest way the difference between Geneticized, townified and defaults? One more thing, can we have as many geneticized custom content - e.g skintones - in the game? Like if I download a set of geneticized skintones, can add more skintones [freckly, tattooed] to it?

The easy answer to your question: Yes, you can add more skintones. You can have as many geneticized skintones as you want, but only one set of defaults. Here is a guide on how to geneticize things: http://rikkulidea.livejournal.com/21779.html

Longer answer with explanation:

Geneticized: All skins in a range that work with genetics.

Towniefied: Generates on townies. Townies will have the possibility of wearing this skin.

Defaults: Skins that replace S1, S2, S3, and S4. Sims with a Maxis standard skin will show up as having the default version of the skin instead.

You can only have 1 set of defaults, but can have as many geneticized/towniefied skins as you want. If you download a set of geneticized skintones, you can add more skintones in between by editing values in SimPE.

For example:

I use Pooklet's Compulsion rehash skintone set with defaults of the same. There are 17 skintones in the set, ranging from very pale to very dark; they are numbered 1-17, with 1 being lightest and 17 darkest. Four of those skintones (numbers 2, 4, 11, and 14) are the defaults that I use. Compulsion Skintone 2 replaces S1, and so forth.

If I just had the defaults in, any Sim who I created with Maxis skintones would show up as wearing the corresponding Pooklet default instead. For example, Pooklet Compulsion skintone #3 is defaulted to S1, which means that when I put defaults in, any Sim who was created with S1 will show up as wearing Pooklet skintone #3. If I was to remove the defaults, they would revert back to their standard Maxis S1 skintone. If I were to breed sims with only the defaults in, standard Maxis genetics apply (i.e. a sim bred from an S1 and S3 sim could have S1, S2, or S3 for their skintone.) Thus, with my defaults in, a sim bred from one parent with the Pooklet default for S3 (skintone 11) and the default for S1 (skintone 2), would look like they got either skintone 2, 4, or 11.

Now, if I have the defaults in along with the geneticized skintones, if the Sim has parents who are skintones 3 and 9, their child could be born with Pooklet skintone 2, 3, 4, 5, 6, 7, 8, 9, 10, or 11. Geneticization allows for a broader range. Many creators, especially at GoS, use Pooklet's geneticization range, so that when people throw multiple sets of geneticized skintones in they get reasonable shades. To make this slightly confusing, the geneticization values are not the same as skintone number (i.e. Maxis S3 does not have a genetic value of 3.) Rather, the Maxis tones are set at geneticization values of 0.1 for S1, 0.3 for S2, 0.6 for S3, and 0.9 for S4. Most people will try to work around this (and will use higher numbers that are off the charts for fantasy skins, which have their own ranges. I won't go into fantasy skins because I don't use them and therefore am not familiar with what the range is, but I think most people geneticize them on a color spectrum, granting, say, 4.00 for red, 5.00 for orange, whatever. I'm making those numbers up - red's probably not actually 4.00, etc, but you get the idea. I hope.)

This is the geneticization guide for Pooklet's compulsion rehash:

01 - 0.075
02 - 0.1 <--This is the genetic value for Maxis S1
03 - 0.2
04 - 0.3 <--This is the genetic value for Maxis S2
05 - 0.35
06 - 0.4
07 - 0.5
08 - 0.525
09 - 0.55
10 - 0.575
11 - 0.6 <--This is the genetic value for Maxis S3
12 - 0.75
13 - 0.83
14 - 0.9 <---This is the genetic value for Maxis S4
15 - 0.975
16 - 1.05
17 - 1.125
18 - 1.2

If you had a freckly skintone that was geneticized at 0.2 in your Downloads folder and you bred a sim with either S1 or S3 with geneticized defaults of Pooklet's skin in, the Sim could inherit Pooklet's tone 2, 3, or 4, S1, or S3 (though S1 and S3 would appear to be Pooklet tones 2 and 4, due to having defaults in.) However, it could also inherit the freckly tone. Similarly, a sim bred from a parent with the freckly tone and a parent with Pooklet skin 5 could have the freckly tone, Pooklet's skin 3, 4, or 5. If the Sim inherited S1 or S3 and you removed the defaults, the appearance would revert to the Maxis S1 or S3. If the Sim inherited Pooklet skin 3 and you removed the geneticized skin from the folder, they would appear to have S2 (because all sims who have their custom skins deleted revert to an S2 appearance.)

If you were to set another custom skintone to have a genetic value on this scale, it would then behave according to Maxis genetics, with the sim capable of inheriting either parent's skintone or any skintone in between.

I hope that helps.

After I typed all this, I found this link: http://rikkulidea.livejournal.com/23079.html
It's probably more helpful than me.

I actually have a default/geneticized set I created myself, but I thought it went from .01 to .99 (on a non fantasy scale) so I'm kinda wondering Juliery, Is there a purpose for the 5 added to the end on some of the numbers (0.975 which i would be assuming is 97)? The tutorial you linked to (which is how I learn to do all this awhile back) didn't explain the scale more in depth other then base values and defaults.

Singleclawdesigns: I geneticized the skintones I use purely for my own use, so some of the numbers I used are quite random, but I would assume that for the numbers like 0.975, extra numbers are used after the decimal point to allow for greater/more precise variation.

For example, you could then have three skintones geneticized at 0.97, 0.975 and 0.98, which would allow you to geneticize more skintones with smaller differences between them than if you just used 0.97, 0.98, 0.99 and so on.

Some people may also use extra numbers after the decimal point in order to geneticize a skintone exactly halfway between two existing skintones - if you had a 0.97 skintone and a 0.98 skintone and you wanted to put another one between them you could use 0.975 as its genetic value.

Incidentally, Julieryc, that's a really good explanation that you gave! :-)

OK so 975 would be a half value without adding the decimal place. Since currently my game is ticking me off may as well see what i can get going with a different skin set.

Edited to add: OK now it doesn't make sense. How would you do a half value of a value less then 10? Wouldn't SimPE see that as the full number or would it work more like this?

.025 (for 2 1/2)
.25 (for 25)

Thank you so much everyone for the help! Julie, I followed your post and the guide you mentioned, and geneticized a batch of skintones! Thanks.

However, I have one more question: Can we have defaults, geneticized/towinified and custom content of the same batch of skintones at the same time? Having defaults, custom and geneticized versions of things will bork my game, no?

I would think that is entirely possible, as that is what the base game pretty much ships with...the default skintones maxis created will show up on townies and are genetic, in other words.

You can definitely have defaults and gen/towniefied versions of the same batch of skintones at the same time - that's what I do. And having defaults and custom skins in at the same time isn't a problem, either, but you have to remember that a sim created with the custom version of the skin will not breed with proper genetics, where sims who use the default will: if you have a set of skintones A, B, C, D that are both custom and set as defaults, if you breed a sim with custom skins A and D, you'll only get a sim with A or D, while if you use the default version, normal EAxis genetics apply and you could get a sim with skintone A, B, C, or D.

However, you may not be able to have gen/towniefied and custom versions of the same skintone in your game simultaneously. (I'm not sure if this has to do with how the individual skintone creator's set it up, but the sets I've used always come with the disclaimer, "customized or geneticized, pick one." You'd have to ask a skintone creator why that's so; my guess would have to do with them using the same GUIDs. But, in general, you can't use both gen/towniefied and custom versions of the same skin in-game together.

This is correct. Townifying and/or genetizing a skin is done by changing one or two numbers. One number if it is one or the other, two if both. The GUID doesn't change, so there cannot be more than one in a game at a time.

However, what happens if one creates a new skintone in bodyshop? Is that its own animal or does it retain the parentskin's GUID?

Oh new GUID but you'd need to work with SimPE to make it genetic, default or townified. You can change the GUID in SimPE too.