Rules: Onset of the Twilight and Death

A dragon’s maximum age is a function of its Charisma score. For a chromatic dragon, multiply the dragon’s Charisma score by 50 and add the result to 1,200. This is the age when the twilight period begins for that kind of dragon. For a metallic dragon, multiply the dragon’s Charisma score by 100 and add the result to 1,200. This difference reflects the fact that metallic dragons are longer-lived than chromatic dragons. Maximum ages for the dragons found in the Monster Manual are given on the table below.   When a dragon’s twilight period begins, the dragon must make a DC 20 Constitution check. The dragon dies if the check fails. If the check succeeds, the dragon survives, but its Constitution score drops by 1. Each year thereafter, the dragon must succeed on another Constitution check in order to stay alive.