Open the cheat console. Press Ctrl+⇧ Shift+C on a Windows computer or ⌘ Command+⇧ Shift+C on a Mac. You should see a text box appear at the top of the screen.

Enable cheats. Type in testingcheats on and press ↵ Enter to do so. You'll receive a "Cheats are enabled" confirmation message on the left side of the window

Go to a Sim. Find the Sim for whom you want to raise at least one need bar.

Review the Sim's needs. Select your Sim to view their needs and make a note of the ones which are low.

Fill up a Sim's needs. Once you've determined which needs have to be filled up, open the cheat console again, then type in fillmotive motive_need—making sure to replace need with a need's name—and press ↵ Enter

  • For example, to fill you Sim's "Social" bar, you would enter fillmotive motive_social here.

Fill all of your Sim's needs at once. If you want to fill up more than one need at a time, you can use the "Make Happy" cheat:

  • Hold down ⇧ Shift while clicking a Sim.
  • Click Cheat Need... in the resulting pop-up options.
  • Click Make Happy

Fill your whole world's needs. If you want to set every Sim's needs to maximum, you can do so by using your Sims' world's mailbox:

  • Go to the mailbox.
  • Hold down ⇧ Shift while clicking the mailbox.
  • Click Alter Needs
  • Click Fill Needs (world)

Remember to refill your Sims' needs periodically. Your Sims will still consume their needs at a regular rate, meaning that you'll need to re-enter your chosen cheat every once in a while in order to ensure that your Sims' needs are still full.