Diamond and Pearl - Singles

The Diamond & Pearl set is the first fourth generation set. As such, with it being the first in the fourth generation, numerous changes were implement. First, the Pokémon cards had their Level return. This was to incorporate the new form of super-card, Pokémon Lv. X. Pokémon Lv. Xs are levelled up versions of the Pokémon. They can use the attacks of the card they levelled up from and also have more attacks to add into it.
Weakness & Resistance had a shake up from this set, with Weakness no longer being just two times the damage. Instead, the amount of extra damage given is now stated upon the card. Attacks have also received an upgrade with some Pokémon having attacks that require no Energy to be used. Finally, Darkness & Metal finally have Basic Energy cards available meaning more Pokémon have energy requirements of those types.