Citadel by the Sea is an AD&D gaming module for 4-8 characters, each of 1st to 3rd level. The fewer the characters available, the higher their levels should be. Characters should be well equipped, with at least one magical weapon apiece, but do not need any particular game experience. It is recommended that at least one ranger character and one elf character be members of the adventuring party, and that no player character be a half-orc. The Dungeon Master should read the entire module carefully before running this adventure; the events are laid out in the approximate order in which characters would normally encounter them, and the text builds the adventure as one reads through it.