I found this soccer ball near some boxes beside the staircase toward the west side of the Tower promenade. It rolls and bounces nicely if you run into it. A little hard to control, but it works. I kicked it over to the center area and almost immediately some other pubbies joined in. I couldn't stop laughing. This shit is amazing.

It'll get stuck occasionally, and it can fall off the Tower, but it always seems to respawn at a couple points beside those boxes at the western staircase. (see the first photo for the general area).

Through nonverbal dialogue with my fellow players, I think the first general Guardian Football rules have been arrived upon.

1. Kick the ball off the tower? You lose.
2. Get the ball stuck? You lose.

The penalty of a loss is death. Hang your head in shame and take a leap off the Tower to your deserved doom.