How to Make Sims Younger on Sims 3

If you have aging on, yes, they will eventually age back up. However, you can disable aging in the options menu.

It should work for any sim.

No, it does not.

You may not have entered the cheat correctly. Try opening the cheat console and entering the cheat again.

Shift click is when you click on something (usually with one of the mouse buttons) while holding down the shift key (the one underneath caps lock that you use to capitalize singular letters).

As long as you're playing on the PC version, yes. Make sure you're entering the cheat properly, as "testingcheatsenabled true", without adding any spaces to "testingcheatsenabled". You also need to hold down Shift as you click on your Sim to access the debug options.

Unfortunately, no. The Sims Mobile doesn't have cheats like this built into the game.

Unfortunately, there isn't an option for this on the console version. While it's possible to cheat on console versions of The Sims 3, you can only age your Sims up with Trigger Age Transition. Aging them down isn't possible.

Try using cheats (ctrl + shift + c, then testingcheatsenabled true.) and shift clicking on the sim want to be younger, and picking edit in Create a sim, then picking the age.