This tutorial is for creating custom Afterschool Activities. I take no credit for any of the programmes, I simply compiled this tutorial to keep all the information together and so other people can learn to make their own

You Will Need:

Sims 3 Package Editor
STBL Creator by Twallan (attached)
Bootstrap Creator by Twallan (attached)
Twallan's Careers Mod
Twallan's Careers Schools Mod
Twallan's UntranslatedKey (This is ONLY for the final stages. Once the activity is installed and working, take this mod out as it is no longer needed)
The BLANK Activities file (attached)

Make sure these are extracted to a file that is easy for you to locate.

Information Needed:
For a simple afterschool activity, there is only a small amount of information you’ll need before you begin. It's best to have this handy, either on paper or on a Word document.
1. The name of your activity.
2. The Days your activity will be on. This is usually two days for teens and three for children. However, if you want your activity to be available to both, this is entirely up to you.
3. The skills your sims will gain when at the activity. This can be as many or as few as you like and can include hidden skills.
4. The ages this activity is available for. This is only for Children and teens.
5. The genders the activity is available for. If the activity is available for both genders, you don’t need to include this in the coding.

Right, on to the coding then!

First off, rename the BLANK Activities file to whatever your activity is going to be. For example, SchoolCouncilActivity.
Open the file with s3pe. You’ll see several files in there.
Double-click on the BLANK.AfterschoolActivities file and change the BLANK to the name of your activity (or a collective name if you’re including more than one activity in the file). For example, BLANK.AfterschoolActivities would become SchoolCouncil.AfterschoolActivities. Press FNV64 and then click OK.
Now, double click on the Bootstrap Creator in the folder. After a second or so, it will generate a file that will look something like this: 00403852583973.dll
Go back to your Activity file in S3PE and right-click on the S3SA file and select Import DLL. Navigate to the folder you extracted everything into and you’ll find your new DLL in there. Select that.
Now, copy the name of your newly generated DLL in the folder and double-click on one of the files named 00403852583973.dll (There are two, one S3SA and one XML). Change the name to your new string of numbers and press FNV64. Do this for the second file too.
Now right-click the XML and open in Notepad. Change the BLANK to the name of your activity OR to the group name you used to rename the first file. Save the changes.
Now would be a great time to save your file.
Now right-click on your first file and open in Notepad. It will look like this:


This is just a matter of replacing the Blanks. It is explained in the file what each line is for, but I'll briefly clarify here:
The Guid is unique to each activity and must not match any other activity. Keep a note of your Guid name as you’ll need it later.
The Skills, Days of the week and ages are self explanatory. Just separate each value with a comma.
If you want to have more than one activity in the same file, just copy and paste the coding and replace with the information for the next activity. For examples of this, see my Afterschool Activities.

Now for the UnhashedKeys. This is where it can get a little tricky.

Paste the following text into a fresh Notepad file:



In s3pe, go to Tools-->FNV Hash. In the first box, put the Guid of your activity in and press Calculate. Now copy the FNV64 value and paste this into the first STR line. So your file should look like this:



Now paste the same number into the second STR line. Your file should now look like this:



Now, copy the whole of the first STR line, excluding the <STR></STR> and paste it into the top box in the FNV Hash and press Calculate.
Copy the FNV64 value and paste it into the first KEY line. Your file will now look like this:



Repeat this with the second STR line. Copy the line, excluding the <STR></STR> and paste it into the FNV Hash and press Calculate. Copy the FNV64 value and paste it into the second KEY line, so your file will end up looking like this:



Save your file as Strings –insert activity name- UnhashedKeys. For example, Strings SchoolCouncil UnhashedKeys.
In the folder you extracted everything into, click and drag your new notepad file and place it over Twallan’s STBL creator. This generates an STBL file for you to put into your activity.

Go back to S3PE and right-click on the Strings BLANK UnhashedKeys and select Replace. Navigate to the folder your activity is saved in and find the new STBL file and select that. Save your changes.
Double-click on the UnhashedKeys and change the BLANK to the name of your activity and press FNV64, then OK.

Now for the English strings!

Open a new Notepad file and paste the following text into it:



Now, the STR line from the UnhashedKeys file become the KEY line in the English strings, so copy the first STR line from the UnhashedKeys file and paste that into the KEY file in the English strings. Your new file should now look like this:



The first STR line is the name of your activity.



And the same applies to the second STR line, so your file will look like this:



And the second STR is the description of your activity. So the file will look like this:



Save the file as Strings –insert activity name here- English. For example, Strings SchoolCouncil English.

Now we need to create the English STBL.

In s3pe, go to Resource-->Add.
Type: STBL 0x220557DA
Group: 0x00000000

Make sure Use Resource Name is checked and change the name to something like Strings –insert activity name here- English (for example, Strings SchoolCouncil English) and press FNV64. Then, go to the instance and change the first two numbers to 00. So as an example, my instance is 0x784F50B53A22A12A. So I change the first two numbers to 00 and it then looks like this: 0x004F50B53A22A12A. Then press OK.

Now right-click on the English strings and select Edit STBL.
Copy the first KEY line from your English Strings, excluding the <KEY></KEY> and paste it into the box at the bottom and press Add. In the large box to the right, you type in the name of your activity.
You then copy the second KEY line from the English Strings, excluding the <KEY></KEY> and paste it into the box at the bottom and press Add. In the large box, you type the description in. Then press Save and commit changes. Now save your file.

Make sure at this stage that you have Twallan’s Careers mod, Careers Schools mod and Untranslated Key mods installed. Now place your activities file into your packages folder and run the game. Click the school (as a child or teen) and select Join Afterschool Activity and you should see a string of coding. Make a note of the numbers at the end, as you’ll need these in a minute.
Close the game and get your Notepad files back up again.
Paste the string of numbers into the files, so they look something like this:

UnhashedKeys



English Strings




Now, copy the first STR line from the UnhashedKeys file and paste it into the FNV Hash again and press Calculate. Copy the FNV64 value and paste it into the first KEY line. Repeat this process for the second STR line and save the file.
Drag and drop the UnhashedKeys over the STBL creator again and replace the STBL with the new one in the activity file. Save your activity file again.
Now right-click on the English strings and Edit STBL. Copy the first KEY lin from the English strings notepad file and, just like before, paste it into the bottom box, only this time press Change. Repeat this for the second KEY line and save the English strings and commit changes. Replace the file in your packages folder and load up the game. You should now have a brand new afterschool activity!!

To add other languages, just create another STBL file and repeat the process. Instead of changing the first two numbers to 00, change them to the numbers that correspond with the language:

English = 00
Chinese = 01
Taiwanese = 02
Czech = 03
Danish = 04
Dutch = 05
Finnish = 06
French = 07
German = 08
Greek = 09
Hungarian = 0A
Italian = 0B
Japanese = 0C
Korean = 0D
Norwegian = 0E
Polish = 0F
PortugueseStandard = 10
PortugueseBrazillian = 11
Russian = 12
SpanishStandard = 13
SpanishMexican = 14
Swedish = 15
Thai = 16

And there you have it! One (or maybe several) fully functional afterschool activity (or activities) for your younger Sims! Feel free to ask questions, and I'll do my best to answer them