Vulcanus (ボルカルス) pits one monster player against 1-3 teams of humans, who must co-operate in order to take down the monster. In more detail, the monster "Volkars" has suddenly appeared from the crater of Mount Fuji, the monster being a ruthless giant that erupts lava from its whole body and that continues to evolve and grow as it creates a path of scorched earth on its way toward Japan's capital, Tokyo. The more casualties you create, the more areas you burn, and the more landmarks you destroy, the closer the monster player is to victory. The Japanese government has set up a "Monster Disaster Emergency Headquarters", and the human players facing off against Volkars must learn how to repel monsters by evacuating citizens, extinguishing fires, deploying Self-Defense Forces, and conducting investigations. The more research you've conducted, the more options you will have for your strategy, and ultimately you will be able to manage the situation with a direct attack on the monster. Sometimes the monster can detect the humans' operation and ruin their plans, so will Tokyo perish in the end? Or will the monster fall instead?