Make Your Sims Immortal on the Sims 3

Do you want your Sims to be immortal on the Sims 3? This article will show you how!

Please note that the first method in this article uses cheats. Two alternate non-cheat methods follow.

Steps

Create your Sims and move them into a house. The traits that they have are irrelevant, so you can make them act like whatever you want. If you have already done this, then you can skip this step.
Click on Options and on the Game Options. Uncheck the box that says "Enable Aging." The picture shows you where what box it is.
Open the cheat box by pressing Ctrl+Shift+C on your keyboard. Then, type in "testingcheatsenabled true".
Shift click on the mailbox. Select the option that says "Make Needs Static." This means that your Sims' needs will go up 100% and stay that way.
Go to the cheats box again. Type in "buydebug".
Go to buy debug.
Buy several death flowers. After planting them, harvest them.

If you don't want to use cheats, get the Sims 3: Generations. When your Logic is at 10, you can make a potion called "Age Freeze" using the Chemistry Station.
Be careful when doing cheats. It can make your game glitch and lag!
You can also simply turn off aging in the options, this is the easiest way, however it will also stop all other sims from aging.
resetSim [FIRSTNAME LASTNAME] is useful for avoiding death.
If you click on change to immortals, you can never get normal humans back unless you create a new family!
With the "Testingcheatsenabled true" activated, you can increase the sims needs by moving them to the right (e.g. Hunger, fun, hygiene, energy, etc) and delete moodlets.
If Generations is installed, you can get a Young Again potion. Drink that and then get a Age Freeze potion.
To be immortal in the base game, build your gardening skill to 10, find and plant Special seeds (look daily near the dome of the lab), and build a crop of life plants. Eat the fruit until your age meter goes to zero (you'll be stuffed), and then eat at least one fruit a day. Your Sims will never age. If you are efficient you can do this before becoming a full adult, and remain a young adult. A side benefit of this strategy is that in the process you will also grow money trees and become wealthy, as well as death flowers (just in case).

It is suggested you save at least once every other sim day- The Sims 3 has a habit of freezing and closing down.