A butler directive unit (BDU) is a consumable accessory containing a set of instructions to operate a butler bot. At least one BDU must be installed in order for any butler bot to operate.
How to Obtain
BDUs are looted from chests, or can be obtained by trading for them with other players. You can also purchase them as part of the Butler Bot packages in the crown store: each package includes 2 BDUs.
How to Use
To use a BDU, you must first install it. To install a BDU, visit Pocklington and look on the map for ButlerBot HQ. As of March 2015, there are five directive programs: Draining/Dumping Liquids, Mining, Placing, Excavating, and one called "Move," which remains rather mysterious. Each different program requires you to complete a different challenge. You must navigate a series of dangerous traps in order to get your BDU installed. Once you reach the end of each challenge, you must click on the installer, which will consume one BDU from your inventory and install the program into your butler bot.
Different commands require different types of butler bots. For example, the ability to excavate earth backdrop requires you to have at least a diamond butler bot. Note that as long as you have any type of butler bot in your inventory, you will be able to install any program, even if the bot that you have is incapable of actually carrying out that command.
Before ButlerBot HQ was created in Pocklington, three installers were placed in the competition world called "The Factory." Those three installers remain, and include the mysterious "Move" command.