A person reaches into the sack, grasping what feels like a hand within it. If she decides to pull it out, she will herself be pulled into the bag, only to emerge again immediately. It will appear to the other players as if the sack sucked her up and then vomited her out again. She will be unharmed and unchanged, with the exception that her visual perceptions will be reflections of what is actually there (e.g., the inn will be on the opposite side of the street, its sign will say, NNI, the crippled beggar will be missing the wrong foot, etc.). The character will take a Perception (or equivalent attribute) penalty until the spell wears off, usually within 24 hours of game time. (GM's discretion, of course.)
Someone reaches into the sack and pulls out a leather ball, which then proceeds to bounce around taunting the player who drew it, challenging her to a game of your choice. The ball will not relent until the character plays a match against it, and will continue to trash talk its opponent throughout. As you can imagine, it is incredibly difficult to succeed at a sport in which the ball is playing against you. If victorious, the ball will follow the character around, bouncing and bragging loudly about how much better it is at whatever sport was chosen, telling anyone who will listen about the loser's crushing defeat. If the ball is on the losing end, it will slink back into the bag, vowing to beat the player at a rematch. The ball recalls previous matches each time it is drawn, and it holds a grudge.