The Deployer uses items in much the same way a player does, as if right clicking.
The Deployer has nine slots in its inventory. (You can feed it with Pneumatic Tubes). Upon receiving a redstone pulse, it examines its contents in order (left-to-right, top-to-bottom), and when it finds a non-empty slot, it emulates a right-click action when holding this item. It can place blocks, fill buckets, empty buckets, till dirt, make fire, and do almost everything that a player can do - except for breaking blocks, which is what a Block Breaker does.
- Deployers can scoop source blocks directly into empty buckets in the deployers inventory, and they can also scoop out of Tanks, so setting up a Pump first is needed if they are to be handling liquids. If using Transposer to remove filled buckets from the Deployer, make sure you set it on a longer Timer than the one sending redstone pulses to the Deployer, otherwise you will take empty buckets instead of full ones.
- You can also set it to drop Sand or Gravel down a hole or swing a weapon as some sort of defensive structure.
- Another interesting feature of the Deployer is, since it simulates the player placing blocks, it can be used to create Snow and Iron Golems, which couldn't be created using pistons.
- It is also possible to upgrade the deployer to an Assembler for more complex uses.
- A deployer cannot deploy a liquid from a bucket into a space where the liquid will flow in any direction. So a liquid must deployed into a space such as a 1x1x1 square with a block on each side and the bottom but not on the top. This also applies to filling bucket.
It should also be noted that a Deployer does not seem to be able to deploy full buckets into tanks, despite being able to fill empty ones from tanks.
(bug) The deployer does not seem to work when placed inside the spawn-protected area