Infamous Second Son is an action-adventure game set in an open world environment and played from a third-person perspective. Players control the main character Delsin Rowe, who can parkour-style climb vertical surfaces like high-rise buildings. Delsin is a Conduit, which allows him to use superpowers by manipulating materials such as smoke, neon, video, and concrete. These materials can be weaponized (such that Delsin can perform melee attacks or fire projectiles from his fingertips) or used to deftly navigate the game world (such as using neon to dash up buildings). Using powers depletes a meter in the head-up display (HUD), which can be replenished by drawing from power sources such as smoke from exploded vehicles. Delsin earns new powers as he progresses through the story, which sees him fight against the Department of Unified Protection (D.U.P.) during missions. Each time Delsin gains a new power set he must destroy D.U.P. Core Relays to learn the basic abilities that correspond to it. Delsin upgrades and acquires new abilities by spending Blast Shards that have been collected, they are scattered throughout Seattle. Players become more powerful in combat by expanding Delsin's suite of abilities. 
Players may choose to act in either a good or evil way. Examples including healing civilians, doing drug busts, and stopping suspect brutality for good, or killing innocent civilians and killing instead of apprehending enemies. Several times throughout the story, Delsin finds himself in a scenario where he must make a good or evil choice, such as whether to encourage Conduit vigilante Abigail "Fetch" Walker to stop slaying drug dealers, or to train her to become a more prolific killer. Player choices influence outcomes in some later missions. In combat, Delsin may use his abilities to incapacitate foes or obliterate them with headshots. He may choose to open fire on innocent civilians. Delsin's choices manifest in a logo displayed on his jacket and the HUD, which features a blue (good) and red (evil) bird. Performing actions that are villainous gradually change the logo so that the red bird dominates the other, with the opposite happening with heroism. This is a visual representation of Delsin's Karma level, that increases as good or evil depending on his choices. As his Karma level increases, Delsin can acquire new powers that correspond to his play-style (e.g. very destructive powers with high levels of evil Karma) and his jacket also changes. If you have good karma, the jacket completely changes white whereas if evil the jacket turns red. A continual streak of either good or evil actions fills up a bar in the HUD, which then lets Delsin perform a powerful finishing move called a Karma Bomb. 
When not completing story missions, players can explore the city and complete activities such as tagging graffiti spots or killing D.U.P. secret agents. The city is split into districts that are all initially controlled by the D.U.P., but Delsin gradually liberates each district by completing activities. When D.U.P. control of a district falls below 30 percent, Delsin can enter a District Showdown that requires him to eliminate a wave of D.U.P. forces, eradicating D.U.P. presence there.