If you want a stag do with adrenalin and excitement then include a stag activity where all you have to do is Just Jump.
Take Coasteering, an activity for the Adrenalin Junkies and includes jumps from 5ft ledges all the way to 60 foot jumps, ouch.
If that sounds like your bag and can’t get to the coast, Canyoning is a great inland replacement with similar height jumps into deep water but also the added benefit of beautiful scenery and waterfalls.
If you prefer to be attached, go bridge jumping whilst on your stag do in Bratislava or Prague. You are attached to a bungee cord and jumping off a platform in front of your mates, there is no better feeling.
So if you have a stag who wants to assert man hood whilst on his stag do, book an activity where he puts his money where is mouth is.