CTOS Mobile Challenge is a multiplayer game mode in Watch Dogs, where one player is driving within the game and the adversary is using the CTOS Mobile app. PC or console player escapes from police, and mobile app user tries to catch him by controlling ctOS from inside and sending Police Forces to the player.
The ctOS Mobile App User: This user controls from inside the ctOS, hacking anything and sending police forces on the player to slow down and kill the player in time limit.
The PC or Console User: This user escapes from the Police Forces and tries to stay alive until timer ends. PC or console user can't hack city infrastructure if it is in control of Mobile App user.
- This online modes working basis is also used in missions The Rat's Lair and Sometimes You Still Lose.
- This is the only mode where Police Vessels make an appearance in police pursuits.