Event Pokémon are Pokémon that are distributed at Nintendo promotional events, such as movie premieres, expositions, festivals, places like PokéPark, real-life Pokémon Center stores and sometimes found in bonus disks or specially transferred from another game. They typically have a special OT and ID number indicating their authenticity and usually a special promotional Ribbon from Generation III onward. In Generation IV, most event Pokémon are distributed in Cherish Balls, special Poké Balls that exist solely for event distribution. Event Pokémon are usually desired because they are hard or impossible to find in the games, holding a rare item, and/or know at least one special move that would otherwise be impossible to have via leveling up, TMs, HMs, move tutors, or even breeding.
Generation IV introduced obtaining promotional things via Nintendo Wi-Fi Connection. At first, only key items were distributed. These items allowed players to enter areas normally inaccessible. Last June 2009, Pokémon began being distributed via Wi-Fi as well with the distribution of a Jirachi. Owners of the Japanese versions of the Sinnoh-based games, no matter where they are, may use Wi-Fi to receive the Pokémon. Later on, Japan began having distributions occurring simultaneously via events and over Wi-Fi. In March 2010, the Pikachu-colored Pichu became available for North American and PAL versions of Pokémon Diamond, Pearl, and Platinum. This became the first event Pokémon to be available to non-Japanese games via Wi-Fi.
Outside of Japan, there are very few countries or areas of the world where events tend to be held:
Various countries of Western Europe
While it is not unheard of for event Pokémon to be distributed outside of these countries, for whatever logistical reason, it is incredibly rare. Indeed, some countries may see several years pass between promotional events, and most have never had one held in their country. The establishment of wireless internet has made the Nintendo Wi-Fi Connection a much better distribution model to reach Pokémon players around the world.