In hockey we have the term short-handed when a team is down a player or more due to a penalty. Well, rather than giving a player a penalty, the penalized team has to play with all players having one hand/arm tied behind their backs until the penalty ends or until the opposing team scores a goal. This would almost certainly guarantee the opposing team has possession for the entirety of the powerplay and they will most likely score. This should significantly see the number of penalties reduce as teams would think twice before putting their whole team at a disadvantage while on the ice.

This would be hilarious watching a bunch of hockey players swatting at pucks and sticks with one arm without having the ability to properly clear pucks or make passes. It would add a very interesting element and would sure lead to some interesting tactics whenever your team gets a penalty.