at present some mechanism is used, its just not a very good one...
I mean, I have to say, I feel a bit that people are being a bit... I want my cake and eat it too... i want 48 minutes of one guy playing.. but if anything crazy happens, I dont want to be responsible for taking that risk and I want the game to not punish me for taking that risk. I think actually those are exactly the sorts of tradeoffs that make a game fun. You take a risk you get a reward or you else it doesnt work and you suffer the consequences.