Don’t know if anyone has said it yet, but Fallout 3. There is a story quest where you have to ask a radio host named Three Dog information about your father and it’s a percentage based skill check that if you fail it, I don’t think you can progress (unless I am completely mistaken since it’s been more than a half decade since I last played).
To make matters even worse, even at a maximum 100 in speech, the skill check can still be failed. Again, not 100% sure whether or not the Three Dog skill check is even required or if you can just run to the right place to progress the main story, but if you are a first time player you could absolutely screw yourself over not knowing about this.