The £100K Drop

Contestants, alone or in pairs for the first series, or only in pairs from the second to the ninth series, are given £1,000,000 in £50 notes at the start of the show, banded in 40 bundles of £25,000 each. Contestants are presented with multiple-choice questions, mostly either general knowledge, or focused on current or recent events (even events that occur during the airing of the show) with the words of "this week", "today" even "right now", to accentuate the fact that the show is broadcast live. In the original format, the first four questions have four answers, while the next three questions have three answers, and an eighth and final question have two.

The contestants choose one of two categories at the beginning of each round. If they take too long to choose, a coin is flipped to decide. Each answer option corresponds to a different trapdoor or "drop"; only one answer is correct. The contestants have 60 seconds to distribute all the money among the drops as they see fit, however, they were required to leave at least one drop "clear", meaning that no money may be allocated on at least one answer. Contestants are required to place any remaining money bundles onto the drops, as bundles that are not placed on a drop when time runs out are forfeited; contestants who put money on every drop typically face immediate elimination, except on some international versions of the show. The timer may be stopped early by the contestants if they are satisfied with their choice of answers.

After the timer either runs out or is stopped, the drops for the incorrect answers are opened; any money placed on them falls down a chute and is removed from play by security guards beneath the stage, while any money placed on the correct answer is carried forward to the next question. This process is repeated until at any point where the contestants ran out of money and loses, or after the final question; if they were correct, they win any remaining money retained for its answer.

Depending on the series, the time limits and number of answers were as follows:

For the 2010 Christmas specials, any contestants who lost all their money and would otherwise have left empty-handed were presented with multiple doors corresponding to bonus prizes. The contestants would choose which door they wanted and would win what was 'behind' that door. From the 2011 Christmas specials onwards, a new feature was introduced to allow online players to compete against one another. Additionally, a counter was added to the display screen for each drop to indicate how much money had been placed on it, eliminating the need for manual counting.

On 2 January 2012, as part of the Channel 4 Mash-up, Davina McCall played the game with Andrew, her father; the show was hosted by Phil Spencer from Location, Location, Location. A second Channel 4 Mash-up happened in 2013, the show this time being hosted by Alan Carr.

Significant changes to the format were made in summer 2013 for the tenth series. Teams of four, rather than just being strictly pairs, can now play the game. At each question, the player(s) can swap positions with their teammates – two backstage watching, the other two answering the questions onstage. Unlike previous series, there are now just seven questions and no question categories (if a team is playing); with the first three questions having four answers, the next three questions had three answers, and a seventh and final question with only two.

Contestants who answer the seventh question correctly are shown two possible answers for a "Final Drop" question, and may choose to attempt it or leave with their winnings. The Final Drop adopts Double or nothing format, with a maximum potential prize of £2,000,000 for a correct answer.

Starting from summer 2014, contestants could play as individuals again after four years. Prior to that, only Gemma in the very first UK series (as well as five contestants in the Chinese version) had played the Drop as individuals in their countries. The show's title was rebranded to The Million Pound Drop, as the series was also the first to be pre-recorded due to time constraints.

On 14 July 2017, it was announced that the programme would be returning in the daily afternoon slot of 2018, but with a lower prize fund of £100,000 in £10 notes (40 bundles of £2,500 each), and with the name of the show changing to The £100K Drop.[6] McCall reprised her hosting role, and the series format was similar to the 2013 format with only seven questions, with a reduced 45-second timer for the last four questions.[8] The revival ran for three series, the first with 60 episodes, and the two with 30 episodes each, both broadcast in 2019.

Prior to a taping of an episode, each audience, personnel and contestants, before admission is subjected to a prior security clearance. They must also sign their Non-disclosure agreement and surrender any possessions held herein, such as mobile phones and small bags. The studio on the bottom of the stage is shown to have security officers guarding the premises, in order to safeguard the money played in the game, which are actual cash extracted from a bank of undisclosed nature, which security also monitors. This is also acknowledged during the beginning of each episode (and also done so in other international versions as well), but later series had their intro reducing said references in favour of the past contestants moments.[lower-alpha 1][lower-alpha 2]

Episodes usually last between 60 and 90 minutes, although the last episode of the series may end slightly sooner or later depending on the contestants' performance. On 23 June 2012, for the first time in the show's history, the episode was extended to 120 minutes. The following week's episode on 30 June 2012 was 100 minutes.

On 2 January 2012, a special version of the show aired as part of The Channel 4 Mash-up. The special edition was hosted by Phil Spencer and featured Davina and her father, Andrew, as contestants. This special edition was not broadcast live, as the show usually is, but instead was shown in three pre-recorded 20 minute chunks spread throughout the 'mash-up night' at 18:35, 19:55 and 21:40. Davina and her father made it through to the final question with £50,000, but was not won.

The show returned on 4 January 2013 with Alan Carr as host.

On 19 October 2012, a special version aired live as part of Channel 4's UK telethon, Stand Up to Cancer. For this show, the million pounds was doubled (thus making it The Two Million Pound Drop) and a special 16-player celebrity relay team took on the drop for cancer-related charities. A different pair of celebrities handled each question, with the show airing in two segments — questions 1 to 4 at 21:00 and questions 5–8 were later in the evening. Each pair was given just 30 seconds, instead of the usual 60 seconds, for their question.

McCall switched back and forth between the live telethon, hosted alongside Alan Carr and Dr Christian Jessen, and the two Drop segments. The celebrity relay banked £200,000 for Stand Up to Cancer, with the final four pairs wagering the entire amount on a single answer on each question. This special was included in the ninth series of the show (as that series was in progress), unlike the Channel 4 'mash-up' which was a separate edition.

The series' highest-rated episode was 4 February 2011, which was seen by 2.79 million viewers and received a 14.4% share.[12] Ratings for series 10 dropped but remained respectable; the first episode (14 June 2013) was seen by 1.57 million viewers and received a 7.6% share.[13]

During an episode on 5 November 2010, contestants Johnny and Dee were faced with the options Sylvester McCoy, Paul McGann, Christopher Eccleston and David Tennant. They were then asked "Who played Dr Who for the longest period?". The contestants did not know the answer so decided to split their remaining £650,000 between McCoy and McGann. The answer was then revealed to be Tennant and they lost all their remaining money. Tennant played the Doctor from 2005–10. However, viewers began to query the accuracy of this question,[14] saying it was open to interpretation as McCoy played the Doctor from 1987–89, but also appeared at the beginning of the Doctor Who television film in 1996, making his time playing the character technically nine years uninterrupted. After the producers spoke to BBC that McCoy was apprently the correct answer, Channel 4 announced that Johnny and Dee were allowed to return to the show to continue with the £325,000 that would have remained on an episode aired 12 November 2010; they would went on to win £25,000.

• On 2 January 2012 and 4 January 2013, two special programmes aired as part of The Channel 4 Mash-up.
• Celebrity Games was the first time a series had been pre-recorded.
• The eleventh series onwards was pre-recorded, while it was also the first pre-recorded regular series.