EA's The Sims 3 is allows players to create Sim characters and homes. You can also help the Sim characters live out their lives in the game world. At times, whether by accident, old age or your actions, Sim characters will die. To carry the dead Sim's spirit away, the Grim Reaper will appear at the home. With persistence and a bit of luck, you can get your Sim to marry the Grim Reaper.
Create a female Sim to be your primary character. Create an additional Sim to kill. Give the extra Sim the "Unlucky" trait. This trait makes Sims unable to be taken by the Grim Reaper.
Create a pool with a ladder. Select the Sim you want to kill, then click on the pool and click to make your Sim swim. Click the icon to enter "Build Mode." Delete the pool ladder and build a wall around the pool. Click "Live Mode" and wait for the Sim to drown.
Enter "Build Mode," click the hammer icon to demolish objects. Click on the wall around the pool to remove it. The Grim Reaper will appear shortly to claim the Sim.
Select the primary Sim, click near the pool and select "Go Here." Keep the Sim in the pool area until the Grim Reaper appears. Click on him to interact. There are multiple versions of the Grim Reaper. One version will not interact with you, the other will hang around and allow interactions.
Repeat the process until in you are given the interaction option of getting married.
The Grim Reaper will not take the dead Sim due to the "Unlucky" trait. He claims that others are amused by the Sim's misfortune, and brings the Sim back to life for your amusement. This allows you to kill the same Sim instead of creating new Sims to kill. There are other methods of killing a Sim. Removing the door from a room and starting a fire, allowing the Sim to starve and electrocution. Drowning is arguably the simplest and quickest method and should be used due to the number of deaths necessary to achieve a marital relationship with the Grim Reaper. Killing a Sim is the only way to contact the Grim Reaper. He does not have a phone like many other Sim NPCs.