Upon the release of Batman: Arkham Asylum in August, Eidos, Warner Bros. Interactive Entertainment, and developer Rocksteady incentivized sales of the PlayStation 3 edition of the game by including The Joker as a playable character. The tactic appears to have been a successful one, as the PS3 edition of the game has been uncharacteristically keeping stride in terms of unit sales with its Xbox 360 counterpart, respectively selling 290,000 units to 303,000 in August, according to NPD.

　　Today, Eidos and WBIE announced one more perk for those who picked up the PS3 edition of the game, in North America at least. The publishers said today that the Prey in the Darkness Map Pack would be added to the PlayStation Network in North America tomorrow as part of Sony's weekly Thursday update. The free add-on content will be available on both the PSN and Xbox Live in regions outside of North America.

　　The Prey in the Darkness add-on strongly resembles the Insane Night Map Pack, which Eidos and WBIE released to both Xbox 360 and PS3 owners free of charge last week. As with that release, Prey in the Darkness includes two new maps: Heart of Darkness emphasizes toe-to-toe action at the Arkham Pumping Station, while Hothouse Prey focuses on stealthily subduing enemies at the Abandoned Glasshouse.

　　For more information, check out GameSpot's previous coverage of Batman: Arkham Asylum.