The Accuser, commanded by Piett, unleashes its proton beam cannon against a Mon Calamari Cruiser. Proton beam cannons represented formidable energy-based weaponry, predominantly employed by the forces of the Galactic Empire. Their destructive power allowed them to inflict substantial hull damage.
The most well-known examples were the planetary proton beam cannons which formed superlasers, as seen on the original and second Death Stars. These weapons possessed the capability to completely annihilate entire planets.
Additionally, composite beam superlasers of a smaller scale existed, able to render a planet uninhabitable via core destruction. During the Galactic Civil War, an anti-capital ship proton beam cannon was also constructed on the surface of Dubrillion. Capital ship-sized cannons were integrated into the design of both the Eclipse-class and Sovereign-class Super Star Destroyer classes. While capable of searing entire continents instantly, these weapons lacked the power to completely vaporize a planet.
During the Empire's zenith, a significantly smaller proton beam cannon was installed on the modified Imperial-class Star Destroyer, known as the Accuser. Several decades later, Booster Terrik equipped his personal Star Destroyer, the Errant Venture, with a comparable weapon reportedly based on the designs of the Darksaber project. Furthermore, the Lancet Aerial Artillery vehicles utilized by the Empire were outfitted with fighter-scale proton beam cannons.