Imagine this: You're walking down the road when, suddenly, bandits spring out of the bushes! They say "We're going to kill you and take your stuff!"
They refuse any further conversation than this. They automatically know where you are so there's no avoiding the encounter with stealth. Invisible walls form a sphere around you so there's no escape until all the bandits are dead. You fight to the death, collect the loot and XP from the bandits, then the game otherwise continues as if that encounter had never happened.
My opinion is that this has absolutely no place in a roleplaying game