An ion cannon is a fictional beam weapon described as firing beams of ions (atoms or molecules with an electrical charge). Ion cannons appear in movies and television shows that have a science-fiction based setting. Ion cannons are also present in several games: Homeworld, Homeworld 2, the Command & Conquer series, Unreal Tournament 2004, Ogame, Ratchet & Clank: Up Your Arsenal, and StarCraft, for example.