Class collective rewards and punishments
You can let the winning team draw lots to punish the losing team, let the winning team send three people to draw lots, put a small bucket, put ten or twenty brands in the bucket and write down the punishment. For example, write an article that allows three people in the unsuccessful group to get the lowest score to write a teacher's punishment. Or run laps or something. This can not only play the role of punishment and reward, but also encourage the failed team to study hard. There is no need for class fees and so on. Students should like to play lottery tickets and so on.