Baptisms for the dead take place within our temples. This practice gives those who have died the chance and opportunity to have this ordinance performed for them by proxy, and they are able to choose whether they want to accept that ordinance work or not. When our youth reach the age of 12, they are able to enter the temple if they pass a worthiness interview. They are able to perform baptisms and confirmations for the dead, but not the other ordinances until they receive the temple endowment for themselves.
I have many special, sweet, and sacred memories of the times I was able to perform baptisms for the dead in the temple as a youth. I am grateful that I still get to do so on occasion as an adult. It is a beautiful ordinance. I love the symbolism. And there is an unmistakeable joy knowing that the first step to salvation has just been made available for another child of God.