500 Questions

Season 1

Each contestant's run is divided into ten rounds of 50 questions each. Each round has ten categories (one of which is always "Random", consisting of general knowledge questions) with five questions each. The contestant can choose a question from the categories in any order. Whenever the contestant answers a question correctly, the correctly-answered question is highlighted silver within its category. Answering a question incorrectly results in a "wrong", with three wrong answers in a row eliminating the contestant. Also, whenever the contestant incorrectly answers a question, it is highlighted in red under its category. However, answering any question correctly will erase any wrongs the contestant has accumulated.

Standing across from the contestant is the challenger. The challenger will also occasionally answer questions per the question descriptions below. In addition, if the contestant has accumulated two wrong answers, the challenger chooses the contestant's next category in hopes of knocking out the contestant. Successfully doing so results in the challenger taking the contestant's spot, and starting their own journey towards 500 questions. If a challenger fails to eliminate a contestant in a round (i.e., within 50 questions), then the challenger is eliminated and a new challenger takes over. This is the only means by which the challenger can be eliminated.

If the contestant completes a board of 50 questions, the money won on that board is guaranteed. However, any wrongs that a contestant may have at the end of a round carry over into the next round. If a contestant is eliminated, only money banked in previous rounds is awarded; all money in the current round is lost. The exception is the "milestone", which occurred on the 25th question of a round. If the contestant answered the question correctly on the first response, the contestant received a guaranteed $5,000, separate from the bank (in addition to earning the standard award for the question). There are no bonuses for completing individual categories or rounds. The top prize for reaching 500 questions has never been stated on the show.

There are four types of questions, which are randomly distributed throughout the board. The type remains unknown until the question is selected.

Season 2

The game play between season 1 and season 2 remains the same, except for the following rule changes:

With all bonuses removed from the question rounds, the top prize for a contestant is $500,000 (that is if they answer all 500 questions correctly). ABC, MGM Television, and Warner Horizon Television have not confirmed if there are any additional bonuses for completing all 500 questions.

Season 1

Season 2

Season 1 (2015)

The two Thursday-night episodes (2 and 7) were two hours in length.

Season 2 (2016)

Episodes 1, 4 and 5 are two hours in length.

Germany

RTL Television commissioned a local version to air in Germany in 2016 called 500 - Die Quiz-Arena (500 - The Quiz Arena) and hosted by German Who Wants to Be a Millionaire host Günther Jauch. Answering all 500 questions will bring the total prize up to €2,500,000, which has yet to receive in the first series of five 90-minute episodes.

United Kingdom

On November 27, 2015, Wall to Wall Media picked up the rights to air their own version of the show on ITV. It began airing on August 22, 2016 with Giles Coren as the host. The format is somewhat different from the U.S. version. Rather than contestants trying to answer 500 questions, there are 500 questions on the board and 50 of them are used per episode. Each correct answer adds £500 to the bank. If a player gets three questions in a row wrong, their challenger takes over the game and the bank. The player that makes it to question 50 wins the money in the bank (up to £25,000) which resets each episode, and may return in the next.