You mean to ask if you want to make an effect based on the failure of a PC's action? It depends on the narrative who it would affect, but it can anyone based realistically on what the affect does.<br/><br/>My action failed and you actually critically defended against it too. You should be able to (IMO of course, someone can correct me if wrong) spend any doomdie you have to cause an effect aside from that. The sides should just decide how powerful it is.