Blue Card

The Blue Card (ブルーカード) appears throughout Digimon Tamers and Digimon World 3.

Digimon Tamers
The Blue Card (ブルーカード) contains an algorithm that was created by Shibumi. It exists to create digital connections and does so in any way possible, much like the Digi-Gnomes. The Blue Cards use emotions and faith to make ideas real, and as a result, any card can be transformed into a Blue Card once you understand how they work. Also, due to this nature, it can be used in many different ways.

The swipe of a Blue Card into a card scanner or a similar card reading device can transform the device into a D-Power, linking a human together with a Digimon as a tamer and partners. When this happened, a Digimon in the would be brought across the dimensions and bio-emerge into the Real World.

Kazu created a facsimile of the Blue Card, which Takato later used to help Growlmon digivolve to WarGrowlmon.

Similarly, the Blue Card algorithm was used to summon into the Real World.

Swiping a Blue Card through a D-Power will release 's powers and allow the user to matrix digivolve to Ultimate. When used in this way, the Tamers call them "Matrix Digivolution" cards.

The Blue Card algorithm was also used to bring Digimon across between dimensions passing from the Digital World into the Real World.

Digimon World 3
The Blue Card is used to go between the east and south sectors. When Junior talks to the tricky Guilmon, he gives him a false Blue Card called a 8lue Card. When Junior talks to him again in the basement of the Forest Inn, he gives him a real Blue Card.