It is acquired by completing Heartache by the Number, Rose of Sharon Cassidy's companion quest, the peaceful way, by obtaining evidence against Alice McLafferty and Gloria Van Graff in order to have the NCR justice system deal with them.
Rose of Sharon Cassidy receives +50 HP.
- Calm Heart does not have a Vault Boy image, even in the Pip-Boy 3000, by reason of it being a companion-only perk.
- It is possible to gain both this and the Hand of Vengeance perk, by collecting and turning in the evidence against the two targets, and then going back and killing them.
- This perk was bugged prior to patch 18.104.22.168x. Prior to the patch, Rose of Sharon Cassidy was granted 50 points to her current health total as oppose to 50 points to her maximum health total. As such, the first time Cass took 50 points of damage, the benefit would be lost forever.