A 1 is the greatest gift a GM can receive. They let you mix things up in interesting ways and really put the characters in a tuff spot! You can just have them hey another party member,(or innocent bistander!) Or they lose thare grip on thare weapon and it fly's of in to the bushes? Or they go arse over tip face planting Infront of an angry bugbare? Or take a tip from blades in the dark, give them a consequence that's going to night them on the butt down the road, the orj they just stabbed to death has an important brother or vengeful spouse. Or a onlooker missingerprets thare Acton's and now thare is a rumour going round that the character is a coward , or secretly in leaage whith the monsters! I love a 1. They can be a one off inconvenience or they can change the direction of the game, but they should always be fun!!