Four of Diamonds (Netflix)

Manga
OVA
Netflix
Netflix S1
Netflix S3

Four of Diamonds (ダイヤの4, Daiya no Yon), also known as "Light Bulb" (でんきゅう, Denkyuu), is a game featured in Episode 5 of Alice in Borderland.

Players have to guess which switch (A, B, or C) turns on the light bulb.

As a Diamonds challenge, the game focuses on intelligence, logic, and analytical problem-solving.

Overview[]

Set-Up[]

Location:
Reservoir
Player Limit:
9
Time Limit:
Until the water level reaches the electrical wires

Rules[]

In the main room, three switches are mounted on the wall, and through the door the adjacent room contains a single hanging light bulb.
One of the switches turns on the light bulb.
With the door is closed, players may flip any switch. While the door is open, players may only flip the switch once.
The door will not close if there is a player in the adjacent room or if a switch is flipped.
It is GAME CLEAR if the group correctly guesses which switch turns on the light bulb.
It is GAME OVER if the water rises and touches the wires above.

Explanation of 66% Probability[]

Tatta states that after failing at the first switch, there is a 50% chance that they will guess correctly, but Ann corrects him that it is 66%.

The probability that the first tested switch will work is 33%.
The probability that the first switch will not work is 66%.
Of the 66%, there is a 50% chance that the next switch will work. 50% of 66% is 33%.
Adding the probabilities 33% and 33% together, one has 66% of guessing the correct switch.

Ann's calculation accounts for the bulb lighting up when the first switch is flipped; Tatta's does not.

Solution[]

The correct answer is Switch A. Despite seeming like a game of luck, the Four of Diamonds game rules actually provide all the necessary leads to solving the game with a 100% chance of success.

As stated by Arisu, electricity generates heat, which means if the light bulb is hot, it was turned on before. According to the rules, any switch can be flipped while the door is closed, so Arisu asks Kuina to shut the door and flips Switch A. After a while, he turns it off and asks Kuina to open the door and touch the light bulb. The heat is an indication that the answer is correct, however, to ensure the logic is valid, Arisu flips Switch B and sees that the light bulb does not react. It leaves the group with a switch that made the light bulb hot and another unknown switch, hinting at the right answer.

Game Result[]

Arisu	GAME CLEAR Found the right Switch to turn on the light bulb	Ann	GAME CLEAR Players solved the game before getting electrocuted
Kuina	GAME CLEAR Players solved the game before getting electrocuted	Tatta	GAME CLEAR Players solved the game before getting electrocuted
Joe	GAME CLEAR Players solved the game before getting electrocuted	Sakura	GAME CLEAR Players solved the game before getting electrocuted
Unnamed Player		GAME OVER Touched a live wire and got electrocuted

Gallery[]

Trivia[]

This is the first and only Diamonds number game shown in the Netflix series.
According to Ann, Four of Diamonds is the last numeric Diamond card needed at the Beach to assemble the full deck.
The Netflix adaptation of the Four of Diamonds game has a lot of game and plot differences compared to its manga version:
- in this version, Arisu joins Ann, since she is instructed to test him to be a Beach executive. Kuina and Tatta are also in the group alongside Joe, Sakura and one unnamed player;
- the game venue expands further to take place in an underground sewer reservoir;
- the electrical wires are replaced with an entire electrical transformer;
- while Ann is repeating the rules of the game, an unnamed player foolishly touches the wires and dies, electrocuted;
- Arisu solves the riddle instead of Ann.