The Castle Doctrine is a massively-multiplayer game about burglary and home defense by Jason Rohrer.
The game is currently in [[public alpha testing and can be joined for half price.
Overview
Though the game is played online with the full population of active players, interaction is asynchronous, and players never see each other directly. Each player has a house and starts with a limited budget to build security systems for their house. The goal of construction is to keep other players out through tricks, traps, and puzzles. A player can also purchase burglary tools and attempt to break through the security of other players' houses.
Death, at any point in the game, is permanent and forces the player to restart from scratch with an empty house and limited budget.