Red Dead Redemption is an adventure western, a kind of spiritual successor to the game Red Dead Revolver. Most of the game takes place in 2011 during the decline of the Old West. The game's hero, John Marston, a former criminal, is planning to find and eliminate former members of his gang, but his wife and son are taken hostage by the government, aiming to turn Marston into a government bounty hunter. He has no other choice but to betray three former partners.
Players can interact with environmental objects and engage in combat with enemies using various weapons. The main mode of transportation in the game is horses, each breed having different properties. However, in order to use them, they must first be caught and broken in.
Additionally, players can participate in different events they encounter while exploring the West: public executions, conspiracies, attacks, shootouts, and fending off animal attacks. For example, if a character sees a gang attacking a town, they can shoot them down and receive a bonus for it. Players can also engage in duels, bounty hunting, gambling, herb collecting, and hunting animals for their skins and meat.
Red Dead Redemption also employs a morality system to accumulate positive or negative 'fame'. To accumulate positive fame, the player must arrest a bandit alive rather than killing him, or free a hostage. Negative fame can arise if the hero commits a crime: robbery or the murder of an innocent townsfolk. This also reflects on the behavior of other characters around Marston: if he has negative fame, citizens feel uncomfortable around him, and sheriffs promise to kill him at their next encounter; if his fame is positive, citizens and sheriffs greet him. As the indicator increases, bounty hunters doubt their ability to kill him, and people flee. Marston can shed fame by covering it with a bandana.
In battle, characters can hide behind rocks and shoot from behind them. Shootouts and firearms play a large part in the game. All shootouts are conducted from a third-person perspective.
The game also has a multiplayer option, where up to 16 players can play.