The jet-black smoke not only occludes vision, but overpowers smell with the harsh odor of burnt circuit board.
A smoke grenade is a single-use item which can be thrown to create a cloud of smoke lasting for one turn. The smoke blocks vision, but also alerts guards who see it. The smoke cloud has a radius of 3 tiles, and disappears at the start of the next player turn.
Each tile of smoke acts as tall cover, blocking line-of-sight, but not blocking movement. Units cannot be seen through the smoke cloud, even if they are not inside it. Units inside the smoke cloud cannot see anything or be seen, with two exceptions: