This game is an oldie, but a goodie. It gets students talking and thinking critically to guess the unspoken rule. Even better, there are no materials, and if you can think of a rule and a few good examples on the fly, it’s no prep, too!
To begin, think of a rule for items on the picnic, but don’t tell the class. For example, “must contain the letter E,” or, “must be countable.” Tell them you are going on a picnic, and give examples of 3-5 items you are taking with you, to give them hints about your rule. Then, elicit from the students what they would take. If their item doesn’t fit your rule, tell them they can’t take it.
If you have very large classes, have students work in twos and threes to keep time between turns to a minimum. In any case, set a time limit for each person or group making a guess (30-60 seconds max., according to their level), or they are out. The student or group to guess the rule wins.
When I play this with my students, suggesting an item that doesn’t match the rule or guessing the wrong rule doesn’t get anyone out. The time limit is to keep the game moving, and disqualifying students for not making guesses keeps students from just listening to other guesses to guess the rule without contributing otherwise.