Pokémon Diamond (ポケットモンスター ダイヤモンド, Poketto Monsutā Daiyamondo?, Pocket Monsters Diamond) and Pokémon Pearl (ポケットモンスター パール, Poketto Monsutā Pāru?, Pocket Monsters Pearl) are role-playing games (RPGs) developed by Game Freak and published by Nintendo for the Nintendo DS. With the spin-off Pokémon Platinum, the games are the fifth installment and fourth generation of the Pokémon series of RPGs. First released in Japan in 2006, the games were later released to North America, Australia, and Europe in 2007.
Like previous Pokémon games, Diamond and Pearl chronicle the adventures of a young Pokémon trainer as he/she trains and battles Pokémon while also thwarting the schemes of a criminal organization. The games add many new features, such as Internet play over the Nintendo Wi-Fi Connection and changes to battle mechanics, while including older game concepts such as Pokémon Contests. The games are independent of each other but feature largely the same plot and, while both can be played separately, it is necessary to trade between them in order to complete the games' Pokédexes.
The games received generally favorable reviews. Most critics praised the addition of Wi-Fi features and felt that the gameplay, though it had not received much updating from previous games, was still engaging. Reviewers were divided on the graphics, however; and the audio was criticized as being primitive. The games enjoyed more commercial success than their Game Boy Advance predecessors: with around 15 million units sold worldwide, Diamond and Pearl have sold around 1 million more units than Ruby and Sapphire and almost 3 million more units than FireRed and LeafGreen.