Oh you match the pieces with the pieces of the same color. Let’s see we saw every type of piece was there, inculding queens and kings in different shots. So we have pawn, rook, knight, bishop, queen, king and times two for each color we wind up with 12 teams worth of relics. Or enough for 48 students. Since they only send 16 students at a time this means you might not get matched up with somebody from your run through if they just grabbed the matching piece at random and left. Also fits with the fact that this smaller batch of students was only 16 big. 48/3 is 16 so they can just run this three times over the course of a day (because it’s only been a couple hours at most) and get this sorted out. So Beacon is a very exclusive school if it only allows in 48 students a year. Cream of the crop types.
Also, Jaune and Ruby without knowing what their friends picked also grabbed the matching relics. Of course with Ruby it’s easy cause her sister is a brony and she wouldn’t let her team pick anything else, and for Jaune he doesn’t know who these other two are so it’s just a coincidence. Actually for both it’s a coincidence as none of them seem to have figured out the point of the game.
