What is Fortrun?
Fortrun is the Ratatan’s living ship and traveling base, also described as the Tapostle Ship. Loading tips describe it carrying the Ratatan and encouraging them with song.
The ship appears with the party in the full-release tutorial, and characters refer to it as the adventure prepares to leave.
Fortrun customization
The developer listed Fortrun customization as a future addition on October 16, 2026. The existing living ship and that planned customization feature are separate things.
For other world terms, see Medama and Lunabounce.