Most regions have three Skeleton Forts, while The Devil's Roar has only one, and The Ancient Isles has two Forts plus the Fort of the Damned which was previously a regular Skeleton Fort known as Old Boot Fort. These locations can host the Skeleton Fort or Fort of Fortune raid style world events, while the more unique Fort of the Damned raid hosted solely at the Fort of the Damned island. Skeleton Forts are islands fortified with structures built by skeleton forces. However, they can still hold a fair share of secrets, and plenty of treasure, and host a variety of enemies.
Small Islands are much smaller landmasses that are not large enough to have the landmarks for Riddle Maps. Riddle Maps are exclusive to these islands due to their size and vast selection of unique landmarks. Large Islands are significant landmasses consisting of hills, caves, and the ruins of old settlements. This does not include Sea Forts, Seaposts, Outposts, or Siren Shrines / Treasuries as these are not classified as Islands within the Master Explorer seasonal trial.
There are 74 charted islands found across the named regions of The Sea of Thieves split across 25 large islands, 39 small islands, and 10 Fortresses.
