Yeah I think my friends and I had joked that we should play go fish and super obviously gambling and exchanging money, and when someone came over be like "I mean you guys did say go-fish is allowed." Then if that was banned move to like betting on chess or something and get increasing ridiculous from there.

Also phones were fully allowed during our study halls so if people actually wanted to gamble they could very easily do so on them lol. I think game pigeon even has poker so you could basically do it undetectably via that.