Dragons have always been the most popular and iconic monster type in Dungeons & Dragons, hence the game's name. Not every campaign or one-shot will involve a Smaug or Beowulf-inspired dragon villain to fight, but if a deadly dragon does appear, the player characters' party. Even young dragons are a real threat, and adult and ancient dragons can quickly create a TPK unless the party knows just what to do. Fortunately, most DMs will telegraph a dragon's arrival, so the party can prepare some anti-dragon tactics.
Source：https://www.cbr.com/dnd-tips-fighting-strong-dragon/
