The Drunken Lizard Pub

I am clueless about one of the four chests in the Fort Kuudad basement. The one that says that when "hammer and strength fail," I may gain kingly access by "delicate finesse." I think I know what goes in the other three. Ideas?

Access through finesse. What can you use if a hammer does not "give you access" through a door?

Consider that you are trying to enter a thieves lair. What are RPG thieves famous for? (not the backstabbing^^)

I would probably have rephrased 'kingly access' to 'cunning access'. 'Kingly'; is that a word anyway? We've got 'royal'.