Kingdom Hearts II
Once Luxord invokes "parley" from the pirates' code, he summons four Gamblers to keep a cursed medallion each. Sora, Donald, Goofy, and Jack Sparrow later find one at the Ship Graveyard, promptly defeating it and gaining the medallion back. They then set out to find the other three to return them to the chest and free Jack from the Grim Reaper's curse.
A Gambler does not seem to have an actual body, and is instead an animated set of clothing. Its upper body is comprised of a pink coat with very thin, dark salmon-colored bell sleeves. It juggles dice and playing cards decorated with Nobody symbols in various ways through these sleeves. Either side of its long neck sports a dark salmon colored spike like those on the Nobody logo, and the Nobody's "head" has the same shape. The Gambler's lower body is a faded pink gown that widens near the base and is decorated by several small, white Nobody logos. Its feet are long, flat, and black. The Nobody's lower and upper bodies are not directly connected in any way, and the two halves will occasionally become separated when the Gambler is being attacked. Its overall body structure is meant to resemble the Nobody sigil. Like all Nobodies, Gamblers have astonishing flexibility.
The deck of cards it floats with depict Vexen, Lexaeus, Marluxia, and Larxene, with their respective number in the Organization on the top-right and bottom-left corners. There is also an ace among them, simply showing the Nobody emblem and having an "A" in the corners.
The Gambler is based on the eponymous job class from Final Fantasy.
Kingdom Hearts II
Have everyone equipped with the Jackpot ability. Sora should also have Wishing Lamp. Lots of Gamblers appear in Port Royal, especially where Barbossa is fought The same basic principle (Wishing Lamp does not have to be equipped), can be used in the Underworld Cups, to get a lot of points. This is also a good opportunity to level up summons. Before going into a room with Gamblers, summon Genie. The main reason to summon is if Sora loses a game with a Gambler and he has a summon active, he will never turn into a card or a die.
Gamblers drop the most amount of munny of any enemy, but not by defeating one. Instead, munny is rewarded by winning one of its games. Winning a game, be it a Stop Dice or Card game, forces the Nobody to drop 100 munny and stuns it. If there are multiple Gamblers present, one game will force all Gamblers on the ground to drop 100 munny. For example: Sora engages four Gamblers in a battle and one challenges him to a dice or card game. If he wins and all four Gamblers happen to be on the ground, they will collectively drop 400 munny. Sora can also get a Nobody Guard shield or Twilight Shard by winning. The Jackpot Ability makes them drop 50 additional munny for every Jackpot ability equipped.
Kingdom Hearts III
Thunder magic excels at destroying groups of Gamblers due to their weakness to it. While they can't be easily farmed for munny using their Reaction Command like in Kingdom Hearts II, they still drop 40 munny upon being defeated. Their Card Shuffle attack can be blocked from behind, so using a Dodge Roll isn't necessary.