The top tier of questions is the stack of questions between the second guarantee point and the top prize, thus the closest tier of questions to the jackpot.
These questions have the highest monetary values, and are generally harder than the earlier questions. The drops for giving an incorrect answer within this band of questions are the most extreme, which can result in the most devastating losses.
To create drama and tension, in early versions of the show the studio lighting goes into darkness and this is generally the most dramatic part of a contestant's gameplay.
In certain versions of the show, most notably Super Millionaire, two new lifelines are earned and are only available within the top tier of questions, however unused lifelines from earlier in the game can still be used.
On average, approximately half of all Who Wants to Be A Millionaire contestants have reached the top tier of questions.