In Short Circuit, the military robot struck by lightning is Number 5.
Number 5 is one of the S-A-I-N-T robots developed for military use. During a demonstration, lightning strikes the machine, causing a surge that changes its behavior and appears to awaken independent thought. Number 5 escapes the research facility and begins exploring the world outside its programmed purpose.
The robot’s encounters with Stephanie Speck and other humans drive the film’s comedy and its question about personhood. Stephanie eventually gives Number 5 the nickname Johnny 5, which becomes the character’s best-known identity. The robot insists that it is alive and resists being treated as military property.
The sequel Short Circuit 2 continues the character’s story, but Number 5 is the designation used in the original film. Ally Sheedy plays Stephanie, and Steve Guttenberg plays Newton Crosby, one of the engineers connected with the robot’s creation.