Since people didnt like my first idea. What about this. You have to fight through a dungon and instead of a prize at the end there is a note saying "Congratulations adventure! By reaching the end of "enter dungeon name here" you have the option to purchase this dungeon and turn it into a home or your own dungeon to lure adventurs to their death. Come to "enter location here" and talk to "enter name here" to purchase dungon and furniture and/or traps to kill intruders." After purchasing the dungeon you can purchase either house furniture or traps like drats, and swinging maces. This will also add a conversation option talking about "the powerful item" at the end of "enter dungeon name here". It is up to you as to what you do with the dungeon and you might even be able to convince vampires and bandits to help defend your prize for a small fee.