Infamous is an action-adventure game set in an open world environment and played from a third-person perspective where the player controls Cole and primarily interacts with the world of Empire City through Cole's newly gained electricity-based powers; these are used for movement, offense and defense in combat, and either for better or worse in dealing with the citizens of Empire City. In order for Cole to use his powers, he must have stored electrical power, represented by a node meter on the player's heads up display (HUD). The player can recharge Cole by draining electricity from powered sources or from living beings; recharging also restores Cole's health, which is indicated by blood splattering onto the screen. The more damage that Cole takes, the more blood that covers the screen. When Cole's health is at a critical level, the screen will turn black and white, and if Cole takes a little bit more damage while the screen is black and white, a heartbeat will be heard and will get slower and slower as Cole takes more damage, until it is beating dangerously slow. At this point, further damage to Cole will kill him. If the player stays out of battle long enough, Cole's health will regenerate over time. The game features seventeen different electrical powers, ranging from simple bolts that do not consume Cole's energy to wide-field lightning storms that drain most of Cole's energy.[5] The player can use such powers, giving the player options in certain situations. For example, the player may fire at a generator near foes to cause it to explode and cripple his opponents, then restrain them or fire at the body to kill the enemy.
Due to being vivified electricity, Cole is unable to use vehicles, take up weapons, or swim. Cole easily climbs buildings and other structures and can fall a great height without taking damage. Many powers are acquired over the course of the game; once acquired the player can use experience points, awarded for specific actions, stunts and missions, to increase the power's effectiveness. The growth of these powers is affected by Cole's current Karma level. Starting in a neutral position, it ranges from Guardian to Champion to Hero on the Good side, and from Thug to Outlaw to Infamous on the Evil side. Certain actions, such as stopping to help injured citizens or draining their health to restore Cole's, will affect the Karma level in either direction.[5] Normal story missions may also alter the Karma level. During the game the player will encounter Karma Moments, when the action pauses and the player is told, through a monologue by Cole, of two actions that can be taken, always a good and bad option. For example, one scenario the player is presented with is to either pull a valve and get a spray of tar in his face (Good), or force a civilian to do it for him (Evil). There are also a number of paired Good/Evil side missions in the game; completing one will lock out the other mission but will reward the player with a large amount of Karma towards their selected Karma goal. Completion of these missions helps gain access to unique super powers based on the Karma level. The player is not locked into choosing either Karma path, and may opt to play towards one extreme and later switch to the other mid-game.[5] Doing so will lock out any purchased power(s) in the original chosen Karma sector. In addition to altering Cole's appearance and certain aspects of the game's story,[6] Karma also influences the behavior of the citizens of Empire City, they will come to help Cole in battle if his Karma is Good, but will turn on Cole and throw rocks at him if he has Bad Karma.
Empire City is built on three islands, and the player must work through main story missions on each island before being able to access the next one, though future missions may require the player to return to an earlier island. Each island is divided into a number of sectors, at the start of the game controlled by three different gangs, the Neon District being controlled by Sasha and her Reaper Gang, the Warren District being controlled by Alden and the Dust Men Gang, and the Historic District being controlled by Kessler and the First Sons. The player can undertake a side mission in each sector, once certain main story requirements have been met, to free that sector from gang control, reducing or eliminating the presence of the gang in that sector. Other side missions may also unlock medical stations where Cole will re-awaken should he die. Though Cole must travel on foot he eventually gains powers that allow him to grind along power cables and powered, elevated train rails and to hover for a short time. Scattered around the city are hundreds of 'Blast Shards' which Cole can collect to increase the amount of electricity he can store. There are 32 'Dead Drop' satellite transmitters that help to reveal more of the back-story in the game, all being narrated by John White, or being recordings of Kessler and his experiments.
