Each chosen creature still controlled by the defending player becomes a blocking creature. Each one is blocking the attacking creatures chosen for it. It remains a blocking creature until it’s removed from combat or the combat phase ends, whichever comes first. See rule 506.4.
January 25, 2019 · Ravnica Allegiance
Each chosen creature still controlled by the defending player becomes a blocking creature. Each one is blocking the attacking creatures chosen for it. It remains a blocking creature until it's removed from combat or the combat phase ends, whichever comes first. See rule 506.4.
February 1, 2014 · Born of the Gods
Each chosen creature still controlled by the defending player becomes a blocking creature. Each one is blocking the attacking creatures chosen for it. It remains a blocking creature until it’s removed from combat or the combat phase ends, whichever comes first. See rule 506.4.
September 30, 2011 · Innistrad
Each chosen creature still controlled by the defending player becomes a blocking creature. Each one is blocking the attacking creatures chosen for it. It remains a blocking creature until it's removed from combat or the combat phase ends, whichever comes first. See rule 506.4.
June 17, 2011 · Commander 2011
Each chosen creature still controlled by the defending player becomes a blocking creature.
April 1, 2011 · Duel Decks: Knights vs. Dragons
Each chosen creature still controlled by the defending player becomes a blocking creature. Each one is blocking the attacking creatures chosen for it. It remains a blocking creature until it's removed from combat or the combat phase ends, whichever comes first. See rule 506.4.
February 4, 2011 · Mirrodin Besieged
Each chosen creature still controlled by the defending player becomes a blocking creature. Each one is blocking the attacking creatures chosen for it. It remains a blocking creature until it’s removed from combat or the combat phase ends, whichever comes first. See rule 506.4.
October 1, 2010 · Scars of Mirrodin
Each chosen creature still controlled by the defending player becomes a blocking creature.
February 1, 2010 · Worldwake
Each chosen creature still controlled by the defending player becomes a blocking creature. Each one is blocking the attacking creatures chosen for it. It remains a blocking creature until it's removed from combat or the combat phase ends, whichever comes first. See rule 506.4.