Although it is possible to acquire a monster in-game, the series is known for the ability to acquire new monsters using Compact Discs. Players can use any readable CD, and the game creates a monster using the CD's metadata. Certain CDs would result in unique monsters: for example, some Christmasmusic albums will give the player a monster of type "Santa". Once the player has two or more monsters in reserve, they can be combined, creating a new monster with traits of both 'parents'. There are twelve basic types of monsters that can be combined, as well as eight special types players can receive as rewards by completing tasks or inserting a CD into the PlayStation. The common types are Dinos, Golems, Suezos, Hares, Tigers, Galis, Monols, Worms, Nagas, Jells, Pixies, and Plants. The rare types are Dragons, Magics, Apes, Ghosts, Hengers, Doodles, Nyas, and Disks. Monsters can be combined to create a new monster with a main type and a sub-type which are determined randomly. Once the player has a monster, it can then be raised to fight other monsters. There are six stats that determine how the monster does in battle: Power fuels physical attacks, Intelligence fuels and defends against energy attacks, Life determines monster's hit points, Skill affects accuracy, Speed helps evade opponents' attacks, and Defense reduces damage received from physical attacks. Monsters train either by doing chores nearby, or can be sent to be trained by experts, where they have the chance to gain new attack techniques. It is possible to increase some of the monster's stats with food or vitamins, but vitamins comes at a price of decreasing one stat as well as shorting the life span dramatically. Currency can be used to purchase items in the game, earned by winning monster fighting tournaments. The game can end if the player runs out of currency to manage the monster. The primary way to advance through the game is through monster fighting tournaments. While in battle, each monster has attacks available to it, some moves are only available at close range, others from a distance. Players cannot control the monster directly in a fight, but can call for their monster to stay away or close in, and attack with whichever move is available at the current range. In Monster Rancher 2 and Monster Rancher Advance 2, Holly, the assistant from this game, cameos as a rancher from the group, AGIMA, for whom the player trains monsters.
Reception
The game received "favorable" reviews according to the review aggregation website Metacritic. Next Generation called it "an addictive yet time-consuming title that deserves to attract a whole new and greatful audience to the narrow niche of life sim gaming." In Japan, Famitsu gave it a score of 31 out of 40. The game was a hit in Japan, with domestic sales above 500,000 units by early December 1997. At the time, GameSpot reported that it was "enjoying brisk sales" in the United States as well.
