Scry is a keyword action that allows a player to look at a certain number of cards at the top of his or her library and put them back in any order.  It primarily features on instants and sorceries, but has also appeared on creatures, an Artifact a land and an enchantment.
Originally Scry was a keyword ability like Flying or First strike. It has now been errata'd to be a "keyword action", like regenerate, attach, or counter. The original cycle of Fifth Dawn instants and sorceries with Scry has been errata'd to have a period after Scry X, indicating that it is no longer a keyword.
- If a spell has scry 2, you look at the top two cards of your library and then decide where you want to put them. You can put both cards on either the top or bottom of your library in any order, or you can put one card on the top and one on the bottom.
- Follow a spell's instructions in order. All spells with scry in the Fifth Dawn set have scry as the last part of their text, so scrying is the last thing you do before the spell is put into its owner's graveyard. Several cards in the Future Sight set have scry followed by another effect, so scrying is done before following the other instructions.
- If the spell is countered, you don't get to use the scry ability.
- There is one card (Eyes of the Watcher) that has a triggered ability with scry. When the triggered ability resolves, look at the top two cards of your library and then decide where you want to put them, just as though the ability were a spell with scry.
Where X is 1: the reminder text reads: "Look at the top card of your library. You may put that card on the bottom of your library.".
Where X is 2 or more: the reminder text reads: "To scry X, look at the top X cards of your library, then put any number of them on the bottom of your library and the rest on top in any order."
- Aaron Forsythe. (May 18, 2007.) "Scry and Keyword Actions", Daily MTG, magicthegathering.com, Wizards of the Coast.
- Mark Rosewater. (May 17, 2004.) "Scry Me a River", Daily MTG, magicthegathering.com, Wizards of the Coast.
- Mark Rosewater. (May 14, 2007.) "The Scrying Game", Daily MTG, magicthegathering.com, Wizards of the Coast.
- Tom LaPille. (July 02, 2010.) "Scry Havoc", Daily MTG, magicthegathering.com, Wizards of the Coast.
- Sam Stoddard. (September 06, 2013.) "How Theros Got Its Scry On", Daily MTG, magicthegathering.com, Wizards of the Coast.