"All at Sea" is an adaptation of the rules for naval conflicts. The official rules were a modified version of the "Warhammer" Boat rules, adapted by Nick Davis and first presented in Games Workshop's "White Dwarf" magazine ("US issue 295"). The game's mechanics centred on boarding parties, with options for ramming actions and naval artillery in the form of ballistae and other siege engines. Model ships are built by hobbyists, just as normal miniature terrain, such as "great ships" of Pelargir, cogs of Dol Amroth and Corsair galleys.