The Last Guardian is a third-person perspective game that combines action-adventure and puzzle elements. The player controls the unarmed boy who can run, jump, climb and perform other actions similar to the gameplay in Ico and Shadow of the Colossus. The player may also need to use the environment to silently move around or defeat shadow-being guards, though initially the boy is weaponless. The guards, although slow-moving, can capture the boy, and if the player is unable to free the character in time, the game will be over. The player's movements are augmented by interaction with Trico who the boy can climb upon and ride.
As stated by Ueda, Trico is "driven by animal instincts", and it is up to the player to guide the creature, "taking advantage of his natural behavior", in order to complete puzzles. For example, the player may have the boy throw a barrel that gains Trico's interest, causing it to move to a specific location. The player may also need to find the way for Trico to sit still in order to allow the player to complete a section, while the natural tendency of the creature is to run ahead of the player. Unlike typical sidekicks in video games, which immediately react to a player's command, Trico will be difficult for the player to control, and may take several attempts to coerce the creature into performing a specific action.
