My favorite thing to watch in the summer olympics is weightlifting, have you ever watched that? 
yea i have,  it is an athletic discipline in the modern Olympic programme in which the athlete attempts a maximum-weight
Now is it two or three different lifts that they compete in?
Two competitors lift in order and the weight are snatched and cleaned and jerk
Ah yes that sounds right.  Which lift do you think they are able to lift more weight doing, the snatchh or the clean and jerrk?
Here is the process, each  weightlifter receives three attempts in each, and the combined total of the highest two successful lifts 
What happens if they fail every attempt?
Good question.A competitor that fails as you asked  gets  an "incomplete" entry for the competition.