In Thunder - Flash, the player takes the role of an american squad of paratroopers.. The squad hails from the 101st Airborne Division 506th Parachute Infantry Regiment (PIR). They landed outsided their designated DZ, and need to find the rest of their squad. The game starts with the player controlling the sergeant and a private. They make their way north towards Brécourt, their target, trying to pick up as many soldiers as possible. The game is played on a 16 by 11 grid of hexes, and the object is to make it from the southern border to the northern border of the map, picking up more soldiers on the way, avoiding capture and death at the hands of the 20 german soldiers around the woods. A simple d6 roll against a base difficulty is made for combat checks, modified by NCOs on either side. In addition, a number of french civilians who oppose the german occupation are scattered around the map and may help the US soldiers. With the exception of the two soldiers the player starts with, the rest of the chits are placed around the map, blank side up, so that there is no way of knowing whether you encounter a german soldier, an american soldier or a french civilian until you issue the challenge (Thunder). US troops respond correctly (Flash), and are immediately incorporated into the squad.