Grief Induced-Kidnapping Challenge
Step 1. Make a family consisting of a elder and his two grown up children.
Step 2. Build up a good relationship between the elder and his grown up children.
Step 3. Kill off one of the elder's children through a traumatic accident (Downing in the pool, getting set on fire while cooking, ETC)
Step 4. Create a unrelated sim who looks almost exactly like the dead elder's child and create a child for said sim.
Step 5. Have the surviving elder's child kidnap the unrelated sim and the sim's child and bring them back to his place. Add the unrelated sim and the sim's child to the household so they don't despawn.
Tutorial over and now the challenge part begins.
There is a win condition for the surviving child and a win condition for the unrelated sim.
Surviving Child Win Condition: The elder genuinely believes that the unrelated sim is his dead child. The unrelated sim and their child are welcomed into the family with the unrelated sim taking up the name of the dead child.
Unrelated Sim Win Condition: Help the elder move on from his child's death in a healthy fashion. Return home with your child afterwards.