Players control Garrett, a master thief, as he goes about a series of missions, most of which are focused around stealing from the rich. As with the previous games in the series, players must use stealth in order to overcome challenges, while violence is left as a minimally effective last resort.

There are a variety of routes through each level and players are able to utilize a variety of playing styles to traverse them.[8] The game contains a variety of ways to distract or kill guards, such as barrels of oil which can be set alight. Levels also contain money and valuable objects which Garrett can steal; these are immediately converted into money which can be spent on equipment and upgrades. Garrett is also able to pickpocket guards and other characters.[9] The player may evade guards by hiding in shadows or around corners and is able to peek around edges and through keyholes in order to track the movements of enemies. Once Garrett has been spotted, guards and other non-player characters will attempt to hunt him down. The developers have stated that the game's artificial intelligence is aware of the level design, and as such guards will know in advance of potential hiding spots that the player may be utilizing.[9][10]

Players may enter a "Focus" mode, which provides several advantages.[9][10] It enhances Garrett's vision, highlighting pipes that can be climbed, or candles that can be put out to make the area darker. Focus can also slow down time, so that Garrett is able to steal more effectively while pickpocketing. Garrett can also use Focus to push enemies or perform debilitating attacks. It can be further upgraded over the course of the game.

Garrett carries a blackjack, used to knock guards unconscious; a collapsible,[11] compound bow, which can be used for both combat and non-lethal purposes such as distracting guards; and a claw, which can be used to grapple onto higher ledges.

An XP system for the in-game growth of the character was meant to be used in the final game, but was later scrapped after negative feedback from fans, and to reflect the fact that the character was already a master thief.[