Green Glass Door
Everyone sits in a circle.The facilitator introduces the game and the object (to figure out what you can bring through the Green Glass Door). The facilitator should start with an example, and then each person around the circle asks the facilitator if they can bring an object through the Green Glass Door. The facilitator answers yes or no. Go around the circle until most of the participants seem to have figured out the pattern. The pattern is that they can only bring things that are words with doubled letters in them. Examples: Jelly but not Jam, Kittens but not Cats, Apples but not Oranges, A Jeep but not a Mustang, etc. If a participant thinks he or she knows the pattern, ask him or her to give an example rather than stating the answer so that other participants can continue to play.
You can create numerous variations to this game. For example, the pattern may simply be an object with the first letter of the person sitting next to you. So if John is sitting next to me, I could take a Jacket through the Green Glass Door, but not a Coat. Harder variations may be an object that ends in a vowel or one that makes a sound (bird, ipod, drums, telephone etc). Another variation is to only use words that start with or contain other words ('beautiful' starts with 'be,' 'pen' in 'suspend, et cetera).