Hidden & Dangerous is about the beginning of the Special Air Service during World War II. You control a four-man squad of soldiers. It is a 3rd person/1st person, tactical action game.

The player controls an eight-man British Special Air Service (SAS) team executing a number of important missions during World War II. The game features soldier selection prior to each mission. A comprehensive load-out sequence is also available where players have access to a variety of weapons and equipment. Mission briefings outline objectives, intelligence on enemy strengths and recommended plans of advance. During missions, players can command directly by toggling through the soldiers in their squad, voice commands or a tactical map which allows for real time control or planned manoeuvres once the map is exited. Missions include, sabotage, search and destroy, POW rescue and resistance aid. Hidden and Dangerous features missions in Italy, Yugoslavia, Germany, Norway, the North Sea and Czechoslovakia. Despite certain historical liberties taken with actual SAS missions and time-lines, the game retains a degree of historical accuracy and intense atmosphere, including realistic wounding as squad members can be heavily wounded or killed by even brief enemy contact.

Hidden and Dangerous Deluxe contains the original award-winning Hidden & Dangerous game as well as the Devil's Bridge expansion pack (new soldiers, weapons and missions in new locations including Poland, the Ardennes and postwar Greece), the game editor, all the patches and updates.