In "Duel Masters", two players play the role of duelists, using the "art" of "kaijudo" (a marketing term created for the North American version which supposedly describes the "art of battling with giant monsters," from the Japanese words "kaiju", strange beast or giant monster, and "do", way or art) to bring their creatures to life to do battle. Players battle each other by placing cards into their respective "mana zones," then using that mana to cast spells or summon creatures into the "battle zone."