Social Events with alcohol- How do you prevent underage drinkers?

[JerichaTheCat]

Hey guys!

So my chapter (and my school) is very small. We have 56 members and for the very first time this semester we are having alcohol at formal (crazy I know ) We have a big pre-gaming problem, which is against our risk management policy. So in an effort to prevent people from having too much to drink before the event, we are providing alcohol so that we can monitor it. This brings in a new problem though. Our rules will prevent under 21 members from buying drinks (we have to check id's twice and we give wristbands) but I know that older members will try to buy for younger members. So what is a good way for us to prevent that? send them to discipline? send them home? fine them? I'm curious how other chapters prevent this and also how they handle this when it happens (cause it obviously will)