Hi Thomas! I'll add that you can go an long way with (a) simply not allowing unfeasible actions, e.g. if the player says they want to kill all the guards then you can come back with "you might incapacitate one of the guards on a success"; or (b) amping up the consequences of failure (e.g. "failure will result in injury and social stigma and going to jail")
That said, this is an issue I tried to address a bit in the design of Mutagen Trail. In that game, the GM can give multiple negative consequences at varying levels of likelihood. There's definitely a simplicity cost to that approach, but if you want more realism and don't mind heavier rules you could try using the Mutagen Trail roll cards for Picaresque.