The Member Card is a Key item in the Sinnoh region games which allows the player to access the Harbor Inn which leads him/her to Newmoon Island. This item was introduced in Generation IV and with the card it allows you to capture the mythical Pokémon Darkrai. It is one of the four Sinnoh based event items, alongside Oak's Letter, the Azure Flute and the Secret Key.
Diamond, Pearl, and Platinum
If the player has the Member Card, they can gain access to Fullmoon Island and Newmoon Island. To do so, the player has to defeat the Elite Four and Champion first. Then, the player has to visit Sailor Eldritch's house in Canalave City. The Sailor's son should be in a deep nightmare. The Sailor asks the player if they could go to Fullmoon Island to get the Lunar Wing, as when he did that himself, Cresselia didn't appear.
When the Player agrees, they reach Fullmoon Island. The player encounters Cresselia initially. Cresselia escapes and leaves behind Lunar Wing. After this, Cresselia can be encountered in the wild in Sinnoh. Upon contact with the Lunar Wing, Sailor's son will wake up and tell the player that there was a Dark Pokémon in his nightmares.
This allows the player to access the Harbor Inn in Canalave City. Inside, it will be a man who says that he was awaiting the player's arrival. The Player then reclines on a bed and reaches Newmoon Island. There, the player can battle Darkrai and catch it. After Darkrai is caught, the player will wake up in Harbor Inn with no one there. When the player will come out, Sailor Eldritch will tell them that they were asleep for a long time. If the player couldn't catch Darkrai, entering the Harbor Inn again will lead to repetition of the same series of events and the player can battle Darkrai numerous times until it is caught.
- Japan - December 1st 2008 to January 15th 2009
- North America - August 3rd 2009 to September 13th 2009
- PAL - August 3rd 2009 to September 13th 2009
- According to the date on the official artwork, the 1st December 1951, is exactly fifty years before the first Japanese distribution of the Member Card. This information is also corroborated up by the in-game description of the Member Card, which states that the last date marked on it was from fifty years ago.
- If the player either flees or causes Darkrai to faint, it can be rebattled numerous times before a successful capture.