Je cite fallout.wikia.com :
"Pass cards are yet unknown items that are randomly dropped by ghouls or centaurs. There are only those two cards existing in Fallout 3. It was rumored to be an easter egg referring to Doom, where keys were represented by blue, red, and yellow cards to open corresponding doors. In fact, after seeking in bsa datas there is only a blue and a red one in meshes. More likely, these colors correspond to the Red and Blue subway lines beneath the city.
The protectrons check for tickets or passes, having the red pass will make the protectrons help you whenever on one of the red line stations, if in possession of the blue pass the protectrons will help you out on the blue line stations by killing enemies found nearby (ie. feral ghouls and raiders). "
Autrement dit, pour ceux qui ne comprennent pas un mot d'anglais, il en existe deux (rouge et bleu) qui sont censés t'octroyer le soutien des robots que tu croiseras dans la ligne de metro correspondant à leur couleur.
Pour savoir quelle station est sur quelle ligne, réfère-toi aux cartes présentes à tous les accès au metro.
