Every now and then a player character does something extremely risky because "it would be fun." What are some good ways to handle this as a GM, for the different styles of play? I like playing non-epic sandbox stories, which makes matters all the worse.
Just the latest example:
DM: You are walking a wide trade route, paved with large white stones. The surrounding hills are homes to small fortresses protecting the city in the distance: Zvezdovryh. Nearing the end of your tiring journey, you approach the huge gates, when something very much out of the ordinary happens – men on horseback rush out of the gates, cutting down the halberdier city guards. The horsemen keep coming and coming, rushing along the wide road under arbalest fire from the walls.
Players 1 & 2 (well to the side of the road): We stay and watch, ready to draw weapons.
Player 3 (on the road): I sprint towards the hills.
Player 4 (on the road): I move to the side of the road, draw my bow and start shooting at them.
DM (to Player 4): At first no one notices you — but when you kill one of the front men, a detachment of five rushes you. Roll dice.
Needless to say, the newly-created, inexperienced rogue got slaughtered. Worst part is, that was 4 hours of character creation versus 1 minute of game time.
Long after the fact we talked and it turned out that we had different ideas of what was happening, so I had not explained the situation clearly. She had expected that the dust from the horses hooves would conceal her, making the riders blind to anything further that several meters. I, on the other hand, imagine stone road through a grassy field.
How could I have handled this differently at the time?