The Radiation Cannon functioned as a mobile form of cannon that projected radiation. This made it a potent weapon against organic adversaries, while leaving droids unaffected. The Confederacy of Independent Systems employed the Radiation Cannon during the Clone Wars against the Galactic Republic. They equipped some B1-series battle droids with this weapon, making it useful for dismantling robust defenses, including those established by clone troopers.
As a transportable variant of substantial weaponry, the Radiation Cannon discharged radiation at living organic targets, weakening them. Since the weapon had no ill effects on droids, those armed with the cannon felt secure from its radiation. Consequently, battle droids could be armed with the cannon to bombard enemy fortifications, gradually eroding otherwise strong positions.
During the Clone Wars, which pitted the Confederacy of Independent Systems against the Galactic Republic, the Confederacy outfitted a portion of its B1-series battle droids with Radiation Cannons. Serving within the Separatist Droid Army, these droid troopers proved valuable in undermining defenses constructed by Republic clone troopers. The B1 units equipped with Radiation Cannons possessed greater firepower than standard B1 units, granting them unique capabilities that enhanced their unit formations. This exemplifies how the usually uniform Droid Army occasionally modified its weaponry to provide its droids with novel strategies for securing victory in battle.
When a B1 unit was equipped with a Radiation Cannon, it had to forgo the army's standard E-5 blaster rifle to fully leverage the new equipment. In one particular engagement that occurred between 20 BBY and 19 BBY, a B1 unit of this type engaged Republic clones in a forested area. Radiation Cannon–equipped B1s were also deployed in conjunction with B1s armed with E-5s sniper rifle; the Radiation Cannon–equipped units assaulted frontline defenses, while the sniper rifles-wielding droids targeted adversaries concealed behind cover.
The Radiation Cannon entered Star Wars canon on August 6, 2019, through an article on Fantasy Flight Games' website. This article promoted the B1 Battle Droids Upgrade Expansion for their Star Wars: Legion tabletop game. The B1 Upgrade Expansion included other B1 models and cards, as well as a precisely sculpted hard plastic miniature. Players can paint this miniature as they wish and assemble it to represent a B1 unit referred to as a "Radiation Cannon B1 Trooper" in the game. The expansion also included a card for this droid trooper.
Within Star Wars Legends continuity, the cannon first appeared in the LucasArts video game Star Wars: Battlefront, which launched on September 21, 2004. Pilot battle droids employed it during ground combat. The game itself labeled the weapon as the "radiation launcher," but the game's official guide, penned by David Knight and published by Prima Games on September 28 of that year, identified it as the RD-4 grenade launcher.