- "A safety link that every robot has, so it can be immobilised, in the pits, for security reasons. Pull that out, and the machine will stop."
- — Jonathan Pearce
Removable links (often just called links and sometimes referred to as safety links or killswitches) are small detachable power switches which are used to activate and deactivate robots competing in Robot Wars and other robot combat events.
Once removed, a removable link automatically cuts off power to the robot's drivetrain and weapons, rendering it immobile and making it safe for transportation, inspection and maintenance in the Pits. It was not uncommon for them to either come loose or fall out completely mid-way through a battle, if a robot was hit in the area where the link was housed. This, in turn, would instantly immobilise the affected robot, with notable cases including Bulldog Breed 3's loss to Hypno-Disc in Series 5 and Apollo's loss to Carbide in the Head-to-Head rounds of the Series 8 Grand Final.
The term failsafe - referring to a completely different component - was frequently conflated with link, even on Robot Wars itself, which led to occasional confusion.
Removable links are roughly rectangular-shaped with power sockets at one end and a wire forming a solid hoop-like extension on the other; the latter feature gives the device a close resemblance to a padlock. They can either be custom-designed or made out of commercially-available power connectors, such as Anderson connectors. The design of removable links allow them to be easily attached to or detached from the robot's electrical system.
Although most robots only required a single removable link, it is not uncommon for robots - especially in the rebooted series - to have two or more independent links for the drive and weapon systems. Additionally, duplicate links are required in order to allow invertible robots to be disabled from the inverted position (see Rules).
Removable links became a required safety device from Series 4 onwards, but in series prior to that the robot's main power switch could take any form. Some pre-Series 4 competitors - such as Disruptor - did not even feature a power switch or removable link at all.
Removable links are required to be positioned in a visible part of the robot's bodywork, accessible to members of the Robot Wars technical crew from behind the arena wall. They must also be clearly marked, kept away from any moving components such as weapons and drive systems, and able to be removed even while the robot is inverted. Most robots - especially in the original series - would have links concealed behind a hinged cover within their armour, which roboteers were required to be able to open without the use of tools.
As of Series 10, robots which are able to drive upside-down must also have a duplicate link which is accessible from the inverted position.