Rockstar Games has announced four brand new, big downloadable content packs to arrive throughout the year for Red Dead Redemption this afternoon. It’ll start with content adding new maps, weapons, and characters and end with content that will introduce the living dead to the western sandbox title. That’s zombies, by the way. In between that, multiplayer gambling games such as Liars Dice and Poker will make their way in, too.

“We want to continue to provide Red Dead Redemption’s fans with a steady supply of innovative new content,” said Sam Houser, founder of Rockstar Games. “Our goal is to continue to pack as much entertaining gameplay and as many surprises as we can into the massive world of Red Dead Redemption over the coming months.”

The full list of upcoming content, as well as all of their additions, can be seen below.

Legends and Killers Pack (beginning of August 2010) – $9.99 or 800 Microsoft Points – New active map locations, characters and more:

• 9 new multiplayer map locations — more than doubling the amount of territories in the multiplayer competitive modes
• 8 new multiplayer characters — play as characters from Red Dead Revolver
• Introducing a new projectile weapon: the Tomahawk, with corresponding challenges for single-player and multiplayer gameplay
• New achievements and trophies

Liars and Cheats Pack (TBC release) – $9.99 or 800 Microsoft Points – New competitive modes, multiplayer mini-games in Free Roam, and more:

• Attack and Defend multiplayer competitive mode and challenges
• New multiplayer horse races, complete with mounted combat
• Play as the heroes and villains of Red Dead Redemption, as well as 8 additional multiplayer characters
• Multiplayer versions of Liars Dice and Poker from the single-player game
• Introducing a new weapon: the Explosive Rifle, with associated challenges available in single-player and multiplayer gameplay
• New achievements and trophies

Free Roam Pack (TBC release) – TBC pricing – Delve deeper into the world of Red Dead Redemption with new modes, challenges and gang hideouts to discover:

• Additional Free Roam challenges
• New action areas and defensive placements
• Posse scoring and leaderboards
• New anti-griefing measures in Free Roam

Undead Nightmare Pack (TBC release) – $9.99 or 800 Microsoft Points – Ghost towns and cemeteries come alive in a West gone horribly wrong:

• Brand new single-player adventure, challenges and quests;
• 8 new multiplayer zombie characters;
• Additional animals unleashed in the world;
• New dynamic events and more;

Unfortunately, it looks like we’ll have to wait on screenshots. The press release that arrived in my e-mail earlier this morning didn’t come bundled with any images.

Stay tuned.