Pokémon Brilliant Diamond and Brilliant Pearl will hit store shelves next week, and as with any new Pokémon arrival, everyone is wondering how many Pokémon will be there. Since the remakes will be released over 15 years and four generations after the original versions of Diamond and Pearl, it could be hoped that some Pokémon from later generations will appear in the Sinnoh region.
However, if the recent rumors circulating on the Internet are to be believed, this is not the case. Those with leaked copies of Brilliant Diamond and Shining Pearl have confirmed that the Pokédex will consist of 493 Pokémon; the first is Bulbasaur and the last is Arceus.
In short, you will be able to acquire all the Pokémon present in the first four generations, but none beyond. This number covers just over half of the 901 Pokémon in existence and also corresponds to the size of the National Pokédex previously featured in the 2006 versions of Diamond and Pearl. It should be noted that this number is based on pre-release copies of each game and may be subject to changes via updates prior to launch.
You'll be able to catch each of the Legendary Pokémon from the first three regions through Brilliant Diamond and Shining Pearl's Ramanas Park, an area filled with Legendary Pokémon. However, you will first need to complete the game and find some hidden collectibles scattered around the Sinnoh region before taking on any Legendaries.
It is always possible for more Pokémon to arrive in the game after release; After all, the two Pokémon Sword and Shield expansions added over 150 Pokémon. That said, no expansions have been announced, and since Pokémon Legends: Arceus looks set to steal the Pokémon spotlight for a while, it's hard to imagine a substantial expansion coming out soon.