The Deployer uses items in much the same way a player does, as if they were right clicking.
The Deployer has nine slots in its inventory, which can be fed 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 and empty buckets, till dirt, make a 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 deployer's inventory, and they can also scoop out of Tanks, so setting up a Pump first is needed if they are handling liquids. If using a Transposer to remove filled buckets from the Deployer make sure you include a delay between the Timer sending redstone pulses to the Deployer and the Transposer, 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 cannot be created using ordinary pistons.
- It is also possible to upgrade the deployer to an Assembler for more complex uses (see recipe below).
- A deployer can deploy a liquid from a bucket, however it has to have a target block that can be at most 5 blocks away. This is the same range as the player's right click.
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.
The deployer does not seem to work when placed inside a spawn-protected area
The deployer can also be used to activate items from Industrial Craft or Equivalent Exchange e.g. Mining Laser or Archangel's Smite. However, one should be careful when using these: If these hit a mob, such as a creeper, the mob will move toward the deployer as if it were a player and attack it, even blowing it up (if the mob was a creeper). Using this mechanism, it is possible to create traps using the deployer filled with these items.
- Deployer doesn't seem to be able to place covers/most half-blocks or have been used by a handsaw, the same goes for the assembler.
- Can bug out and not place sometimes, depending on computer usage on minecraft (not enough memory allocated in single player) or laggy server.