A preview card is a card that is previewed in a supplemental product, such as Duel Decks, prior to the release of the expansion set in which the card is contained. This was first seen in the Multiverse Gift Box, which featured Visions boosters with fixed cards. Another instance were the Lorwyn basic lands in Tenth Edition. The regular practice of preview cards debuted in Shards of Alara, with the card Hellkite Overlord, which was previewed in the From the Vault: Dragons product. Thus far, only cards from a block's first expansion set have been previewed this way, most of them in duel decks.
A similar practice was used in the Future Sight expansion set, where "futureshifted" cards included several cards from Lorwyn/Shadowmoor block: Boldwyr Intimidator, Graven Cairns, Mistmeadow Skulk, and Phosphorescent Feast. Although cards were included that were intended for other subsequent blocks, such as Zendikar (Ghostfire) and what became Scars of Mirrodin (Sarcomite Myr), these cards were not used in those sets.
- Magic Arcana (August 7, 2007). "Tenth Edition’s Preview of Lorwyn". magicthegathering.com. Wizards of the Coast.
- Mark Rosewater (August 26, 2017). "Have we seen the last of duel decks that preview an upcoming block?". Blogatog. Tumblr.