Send an unwanted Sim to a specific spot. Enter build mode and place a wall around the Sim. Do not put else inside the room with the Sim. The Sim will die in two days.
Have your Sim go to the bathroom. While in there, delete the door and he or she will be trapped there until they die.
First take an unwanted Sim and tell him or her to swim. Remove all the exits the and the Sim will die when he or she falls asleep.
Place a Sim in the pool, then enable the move_objects on code to remove the ladders.
Enable the move_objects on code, go to buy mode, and click on the unwanted Sim. A message will appear at the bottom of the screen. Click "Delete" and your Sim will be immediately be gone.
Send your Sim to a certain location. Enable the move_objects on code, then buy some furniture and put it around you Sim. In two days your Sim will be killed.
First build a small box-shaped room and put a fireplace in it. Put carpeting all over the floor. Tell your Sim to light a fire. Once they are in the box. Enter build mode and delete the door.
Wait until a robber enters the house. Enable the move_objects on code and delete the door. Then, enable the move_objects on code again and put any Sim in front of the robber. He will then kill your Sim.