The Black Iron Prison uses Security Robots as mechanical muscle to keep inmates in line in The Callisto Protocol. They are incredibly strong and resilient and can instantly shoot down waves, inmates, or zombies.
These robots are first seen when you crash-land on Callisto, and destroyed units are seen all around the prison after the outbreak. A few security robots show up later as enemies you can avoid or fight.
Avoid Or Fight?
When initially introduced, it’s clear these security robots are formidable enemies and not something to take on easily. The first one is even introduced in a mandatory stealth section, as you cannot fight them at that point. After receiving the handgun, you can destroy them, but not very easily. In later areas, these robots will randomly reappear and, much like the first one, can be sneaked past if they seem to be the easier option as dodging their bullets is not an option.
While sneaking past these enemies will save your valuable bullets, you will also miss out on the loot they drop. Destroying a security robot will have it drop a Decoder, which can be sold at a 3-D printing station for 500 Callisto Credits. While it may take a few bullets to destroy them, the total rewards considerably make up for any lost bullets.
Aim For The Head
When facing a Security Robot, most of its body is seemingly unaffected by bullets. The only part of their body affected by bullets is their head. The easiest way to destroy them is to aim for the head with the hand cannon and land multiple shots as quickly as possible. The Security Robot will lift its right hand to try and guard its face, so be prepared and aim for the left side of its head when firing not to interrupt your shots.
Taking down the robot will require 5 to 6 headshots with an unupgraded hand cannon. Should the robot raise its left hand to fire, quickly take cover and break its line of sight. Getting shot with a barrage of those bullets will mean a certain and quick death. Once engaged in combat with the robot, use the stealth system to sneak around to a new angle to get off a few more headshots. Security Bots will always have the upper hand even with an upgraded weapon; hit-and-run tactics are your friend.
If you are able to break line-of-sight, the robot will continue looking and return to its predetermined patrol path. Whenever you find a robot, watch its movements to see where it goes within a room. From there, find the best ambush spot and a backup one if needed. Shooting the robot in the head will very briefly stun it, allowing for multiple quick shots as long as you’re accurate. Your health in these fights is practically irrelevant as they are able to kill you with full health with retaliative ease.