This has been the Question of many Kaiju fans for along time now. They both have simalair Fire Attacks so they would both cancel each other out there. Godzilla's powerful tail lashes would help him out until Gamera decides to use his Protective Shell to block the barrage . Godzilla Could Use his Brute Strength to hammer Gamera but Gamera Could Fight back with his Spinning attack. In the End Both Monsters Have Stenghts and weaknesses leave a comment saying who you think would win the king of monsters or the gurdian of the universe.