"The Filigree Texts do not compel you to act in accordance with their precepts. They only specify the consequences should you fail."
—Lodus of the Ethersworn

The List

Memory Erosion

Whenever an opponent casts a spell, that player mills two cards.

Commander Anthology Volume II

Whenever an opponent casts a spell, that player puts the top two cards of their library into their graveyard.

Commander 2011

Whenever an opponent casts a spell, that player puts the top two cards of his or her library into his or her graveyard.

Salvat 2011

Shards of Alara

Whenever an opponent plays a spell, that player puts the top two cards of his or her library into his or her graveyard.