There is a single entrance ticket for the museums and galleries owned by the City of Dubrovnik:

Ethnographic Museum, Marin Držić House, Cultural History Museum, Dulčić-Masle-Pulitika Gallery, Maritime Museum, Archaeological exhibitions, Dubrovnik Museum of Modern and Contemporary Art, Pulitika Studio

The entrance tickets are good for seven days from the day of the first visit to one of these institutions.
Entrance is free for residents of the city of Dubrovnik, for members of the professional associations ICOM and Croatian Museum Society as well as for organised visits from schools in the Dubrovačko-neretvaska County.