On Ghost Leg

     Sometimes in manga, I'd see characters use an unfamiliar "Ladder Game" (a.k.a. "Ghost Leg" or "Amidakuji") to make decisions or assign tasks.  I couldn't figure out how it worked, so I looked it up on Wikipedia.  I will here demonstrate how it works and leave you to contemplate the interesting logic of why it works:

      One may play Ghost Leg to randomly assign people to chores in a household, roles in a play, or slots in a schedule--usually when the number of people equal the number of items.  Alternately, one can play Ghost Leg solo to randomly decide between several options, such as what ice cream flavor to eat, place to visit, or gift to give.
      Either way, the creator starts by drawing vertical lines equal to the number of participants and/or options, then by writing in the options below each line.  In an equal participants-to-options game, the creator may then either assign the top lines to participants or let them chose their lines; in a solo game, the player will later choose one top line at random. 

Fig. 1

       To finish preparing the game, the creator then draws random horizontal lines called "legs" between pairs of vertical lines (see Fig. 1).  Alternately, the creator may let each participant draw one leg.  I'll note that I've seen cosmetic variations of this game wherein some legs are diagonal or have curly-cues in the middle, which do not affect how the game is played.
      Finally, each player traces a path from the top of their chosen vertical line to the bottom, following each leg that their pencil meets to its linked vertical line, always continuing down to the bottom, thus pairing each starting item at the top with an ending item at the bottom (see Fig. 2).

Fig. 2

      No matter how many legs one adds, this game will always result in a 1:1 ratio; all top and bottom items will be paired without overlaps.  Fascinating, eh?  The game is also simple to make and play.  I think I may use this game in the future in place of "Eenie Meenie Miney Mo."  :)