Dragon Quest Monsters: Joker (ドラゴンクエストモンスターズ ジョーカー, Doragon Kuesuto Monsutazu Joka) is the latest game to be released in the monster catching Dragon Warrior Monsters spin off series. The game was released exclusively for the Nintendo DS in Japan, December 2006, and in November 2007 in North America. The Dragon Warrior Monsters series is widely popular in Japan, and Joker is no exception. The game sold 593,994 units in the first four days of it's release in Japan, and has totaled over 1.45 million units worldwide since its release.
Like the two Dragon Warrior Monster games before it, Dragon Quest Monsters Joker is all about catching wild monsters and raising them to protect you as you travel the world training for the Monster Scout Challenge. Similar to Dragon Warrior Monsters, Joker focuses on turning a teenage boy into the world's best monster scout, a title that can only be earned by winning the Monster Scout Championships. As a monster scout, the player will need to guide a wayward youth through intense challenges, and ultimately to the tournament championship, where they will face the best and brightest monster masters from all around.
Dragon Quest Monsters Joker features over two hundred monsters to collect and raise, a well as a set of seven islands to explore. The game also gives players the option to synthesize (or breed, in other words) two monsters together to create even more powerful monsters - sometimes of an entirely different species!
Quoted directly from the gameplay booklet included in the North American game box.
"Welcome to the Green Bays, a cluster of mysterious islands that sparkle like jewels in the shimmering ocean! But travelers beware! The islands are not as peaceful as they seem, for they teem with a multitude of monsters both great and small.
Green Bays is also home to the famous Monster Scout Challenge. This renowned contest, held once every few years, determines who will be crowned the world's greatest scout. The challenge is organized by the Monster Scout Organisation, whose headquarters are located on Domus Isle, which lies at the center of the archipelago.
Now a new challenge is about to begin, and the creme de la creme of the scouting world are converging on the islands...
It is time for you to begin your quest to become the greatest monster scout in Green Bays, and in history!"
As the wild card son of the Warden of CELL, a shadowy organization that's existence is unknown to the majority of the Green Bays' inhabitants, you dream of participating in the Monster Scout Challenge. After being locked up for a week for attempting to run away and join the tournament, the Warden has decided that you will go and participate in this year's challenges. Though you are acting as a member of CELL, and for reasons unknown to even yourself, it appears that your father has other plans in mind for you besides participating in the tournament.
It's up to you, the Hero, to collect ten Darkonium crystals, and proceed through the rest of the preliminary challenges. Only after you've met the preliminary requirements will you have a shot at first place in the tournament!
A true loner with a don't-mess-with-me attitude and the son of Warden Trump. He has a style and fashion all his own, and doesn't care what anyone says. The Hero dreams of becoming the greatest monster scout in all of Green Bays, and plans to show off his skill in this year's Monster Scout Challenge.
The disciplinarian leader of organization CELL. His uncompromising approach to his work instill both fear and respect in all of his subordinates, though seems to have the opposite affect on his rebellious son.
A young woman of unknown background who is also competing in this year's Monster Scout Challenge. From the first time the Hero runs into her, it is clear that you two are to become rivals in this tournament. She can be snobby and arrogant, and seems to enjoy taunting the Hero and his efforts to become the greatest monster scout.
The commissioner of the Monster Scout Organisation, and the man in charge of the Monster Scout Challenge. He is a renowned doctor and scientist, and is credited with inventing the Scout Ring. A man obsessed with monsters, his real intentions for holding the tournament are unclear.
A legendary monster who takes many forms, such as a chicken. It is a mysterious creature like no other, for it speaks the human language fluently and belongs to no known recognized monster family.
Throughout your adventure, you will be forced to scout and raise literally hundreds of monsters, ranging in all sizes and shapes. You can attempt to scout a monster as many times as you want during a battle, until the monster either flees or takes offense. The success rate of scouting a monster depends on the strength of your team, as well as the strength and family of the monster you are attempting to scout. Monsters are broken down in families, and there are a total of eight different families that a monster can belong to.
The families are:
In addition to being broken up into families, monsters are also given a ranking; either X, S, A, B, C, D, E, or F (X being the highest ranking). This ranking gives an idea of how quickly the monster will grow, and how difficult it is to synthesize. Usually, the more complex a monster's family tree is the higher the monster's ranking will be.
 The Skill System
Unlike the past Dragon Warrior Monsters games, monsters in Dragon Quest Monsters Joker grow stronger by allocating Skill Points. The player may place these points onto one of the monster's three skill sets, after reaching a certain level (the levels that Skill Points become available varies with the monster). Skill Points will either increase the monster's stats or allow the monster the option to learn a new attack. Some skill sets can be upgraded by maxing them out, while others must be unlocked through breeding monsters who have mastered the skills. When synthesizing, the resulting monster can choose its skill sets from those its parents had, the ones that monster naturally knows, and any new ones unlocked through the synthesizing process.
A monster's skills can also be improved through the use of Skill Seeds. These seeds are scattered around the Green Bays, and can be found at nighttime when the mysterious light they give off can be seen. Each seed give three Skill Points to the selected monster, in whatever category the seed falls under.
 Multiplayer and Wi-Fi
Dragon Quest Monsters Joker is the first game in the series to incorporate multiplayer through Nintendo Wi-Fi. Players are able to connect to a server, where their monster team is ranked. The DS then downloads a set of opponents to battle, in a series of tournament-style challenges. For each battle the player wins they may receive either a monster, or item, some of which can only be obtained by winning online battles. The prizes change daily, and battles can only be downloaded once per day.