HBO brass want to make sure every network subscriber samples new series Game of Thrones. In a rarely seen multi-play, after the series premieres on HBO on April 17, followed by two back-to-back encore plays, the pilot episode will air again at 9 PM the following night, April 18, simultaneously on 6 of the 7 HBO-branded channels: HBO, HBO2, HBO Signature, HBO Comedy, HBO Zone and HBO Latino.