PQ-17 is the first game in the Decision at Sea Series of WWII air-naval games highlighting the impact of reconnaissance, fuel, and weather without the drawbacks of a double-blind system or tedious bookkeeping. Players maneuver blocks on the mapboard, each a force of submarines or surface ships whose identity is hidden from the enemy player until it is located by a successful search and the block is turned up. It may represent one ship or one hundred - or none at all, as it may be a dummy. Cards are used to resolve searches quickly and efficiently; a successful search yields intelligence of varying accuracy, while failure to relocate the enemy in a timely manner results in lost contact and generation of another dummy. Players must also cope with fuel restrictions, using simple rules and the use of markers on Force Displays (where all ship counters are kept until needed for combat), precluding the need for record keeping while preventing unrealistic freedom of action.