This card was given to participants of the Plusle•Minun Tag Battle, held at regional Battle Road Spring 2006 tournaments between March and April 2006. It was reprinted as one of the Unnumbered Promotional cards with updated Generation IV artwork by the same artist and given to participants of the DP Tag Battle, held at regional Battle Road Summer 2007 tournaments between July and September 2007. These cards were necessary for the Tag Battle Rules version of the TCG utilized in the tag battles, which required two versions of this card to be included as part of a normal 60-card deck to initiate a partner switch.
I’d assume the same applies to this card. The non-stamped version is merely a participation prize whereas the stamped one required winning stage 3, presumably meaning that there are 8 times fewer stamped versions.
I’d guess that to win stage 3 you’d have to have first won stage 1 and stage 2? Unless my maths is wrong, I think that means for every 8 people who receive a participation card, only 1 would receive the stage 3 winner card?