The class divides into three lines, facing the teacher. The teacher says a vocabulary word and the first three students in each line have to give the correct response, motion or gesture for that word as fast as they can.
The first one of the three to do it correctly, receives a point and all three students return to the end of their lines. Students keep track of their own points. It is then the next three students' in line turn.
When they have collected three or five or ten (agreed upon before hand) points they receive a treat and sit down. Make sure the class understands, that they are not playing as a team, but individually.