This is not a game but an interesting 'event' you can use to generate some good discussion amongst your group. I would only recommend using this for older groups (16+). Not every group will be comfortable with it, but it has been a fascinating exercise I still remember and reflect on 20 years later.
You need to organise someone who is a good actor, mature, over 18, and who no one in the group will know, to wander into your group's meeting mid way through. They should have a can of beer or bottle of alcohol, and act under the influence, without going over the top.
The reaction of your group can be interesting - how do they handle this scenario? Do they recognise an opportunity to help an outsider? Or do they want to shut them out?
As the leader, you need to carefully determine when to intervene and announce it as a setup, but then move onto a discussion about the experience.