New Game + (or New Game Plus) is a game mode for Dishonored 2 introduced in Game Update 1. This mode imports all runes spent on supernatural abilities, traits of crafted bone charms and upgrades from a finished playthrough to a new one, while also giving the possibility for Corvo Attano and Emily Kaldwin to access each other's powers.
This mode is unlocked once the game is finished with at least one protagonist. Playing several New Game + playthroughs can unlock all powers, upgrades and bonecharm traits in the game without any use of file modification.
Original Game +
Original Game + (or Original Game Plus), is a game mode for Dishonored: Death of the Outsider similar to New Game +. It is unlocked after finishing one playthrough of Dishonored: Death of the Outsider. In this game mode, Billie Lurk will have three of her powers (Displace, Foresight, and Semblance) replaced by fully upgraded Blink and Domino, and a modified Dark Vision (which is fully upgraded as well, but now drains mana continuously while activated, and also reveals bone charms).