The competition is open to any eligible club down to Levels 10 of the English football league system - all 92 professional clubs in the Premier League and Football League (Levels 1 to 4), and several hundred "non-league" teams in Steps 1 to 6 of the National League System (Levels 5 to 10). A record 763 clubs competed in 2011–12. The tournament consists of 12 randomly drawn rounds followed by the semi-finals and the final. Entrants are not seeded, although a system of byes based on league level ensures higher ranked teams enter in later rounds - the minimum number of games needed to win the competition ranges from six to fourteen.
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): How many rounds in the tournament?
12