Dungeon Dice Monsters, or DDM for short, is a board game in the anime and manga series Yu-Gi-Oh!. It is seen in the manga and in the second series anime (Yu-Gi-Oh! Duel Monsters).

In Dungeon Dice monsters, there is a tiled board of 13 x 19 tiles (13 tiles wide) on which play is conducted. On either end of the board sits a "Monster Lord" (on the 7th tile from each side on the row closest to the players) representing either player. Each Monster Lord has 3 Life Points. The first player to lose all their Life Points loses. In the Yu-Gi-Oh! Anime, these were referred to as "Heart Points".

Monster Lord - Also called the Die Master, this is a representation of the player. Dungeon Masters cannot move, attack, or defend. Each has 3 Life Points. The Dungeon Master is not affected by items or abilities that affect monsters in the Dungeon. The only way to destroy the Dungeon Master is by attacking it.

Dice Pool - The 15 Dice a player uses. When a Dice is used for a Summon, it cannot be used again. Players are only allowed 10 Summons in a game, so they will always have 5 Dice left over for Crest rolling.

Crest Pool - The place where a player's Crests (Except Summon Crests) are stored. The Crests rolled are stored in the Crest Pool until a player uses them. A player cannot use Crests from the opponent's Pool.

Dungeon Path - Created when monsters are Summoned, it is needed so players can attack each other and move about the board.

Obstacles - Squares placed on a board, neither player can Summon a monster in such a way that their Dungeon Path would lie adjacent to the Obstacle. Strategic placing of Obstacles can cut off a player's main route of Summoning and make the game much more difficult. In the Game Boy game Dungeon Dice Monsters, later levels have Obstacles placed in such a way to only hinder the human player, giving them a large handicap.

In the manga and anime, Dungeon Dice Monsters is created by Ryuji Otogi (Duke Devlin in the English anime).

In the manga, Otogi creates the game under pressure from his father, Mr. Crown. Mr. Crown lost to a Shadow Game against Sugoroku Mutou (Solomon Muto in the English anime). Mr. Crown wants Otogi to avenge the defeat and harm Yugi Mutou, Sugoroku's grandson.

In the anime, he idolizes Maximillion Pegasus (Pegasus J. Crawford in the Japanese versions) and strives to create a game just as great as Duel Monsters. He emails the specifications to Pegasus, who challenged him to a match of the game at Duelist Kingdom. Using the Millennium Eye to read his mind and thus, easily master the game, Pegasus defeats the creator. However, he was impressed with the game and agreed to market it. This is shortly before Yugi Mutou arrives at Duelist Kingdom.

Upon being defeated, Pegasus goes into hiding, and the contract to market Dungeon Dice Monsters is never signed. Thus, the game does very poorly, and the only shop selling it is the one the creator himself owns. The creator blames his failure on Yugi. In the English anime, he believes that he cheated to beat Pegasus, crushing his spirit. In the Japanese versions, Otogi does not accuse Yugi of cheating to win.

In both the anime and the manga, he cons Yugi into a match by dueling his friend Katsuya Jonouchi (Joey Wheeler in the English anime) and forcing him to wear a dog costume. Yugi challenges Otogi for Jonouchi's freedom, and thus the game begins.

Yugi does poorly early on, obviously having little clue on how to play the game. However, he makes a comeback and defeats Otogi. Otogi admits defeat. In the manga, his father's game shop burns down to the ground.

In the anime, shortly after the match, he receives another email from Industrial Illusions, telling him they will sign the contract to market Dungeon Dice Monsters worldwide. It is later mentioned that he travels briefly to the U.S. to market the product, but later returns to Japan.