Play different.™

Gang of Four Online


Adapted from the card games of ancient China, Gang of Four Online has emerged as one of the most popular online card games to come out of Asia in decades. Simple to learn and fun to play, Gang of Four Online is filled with intriguing strategies. To win, be the first to rid yourself of all your cards, using similar combinations as those found in Poker. But beware – a single misstep may find you in a struggle to survive!

Buy

Your first trial game will always be played against computer opponents, freeing you from any worry as you learn the ropes. The next three can be played among your new Gang of Four online friends. Our community of online players is full of helpful people from around the world who still remember the day they first sat in front of the game and will be glad to lend you a helping hand. So join the gang, come online and play!

“It is rare that a game presents players with this complete, challenging and enjoyable experience.”

The Games Journal

Gang of Four Online includes:

  • Free trial: first four games are free, and unlimited access with purchase
  • Vast online player community with people from around the world always ready to play
  • Auto button in the game lets you cycle through all the possible combinations at any given time

If you want to go deeper:


User Guide

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Probabilities & shuffle

Shuffle used in the online game

During the beta testing period of Gang of Four Online, we were using a purely random shuffle. This was generating many Gang of Four combinations, as predicted by probabilities. Our testers, who were highly experienced players of the card game, complained that this was not in accordance with their personal experience. We changed the card shuffling, in order to reproduce what happens in reality:

  • For the first game, cards are distributed randomly.
  • For the following games, we gather the cards in the order they were dropped. The deck is then shuffled using a "riffle-shuffle"*, i.e. the deck is cut at about the middle, and then cards are re-inserted one after the other.
  • The cards are dealt in four hands, and the hands are given to the players at random.

This way, the number of Gang of Four combination is more like the real game experience.

*See paper of Persi Diaconis and David Aldous : "Shuffling cards and stopping times", American Mathematical Monthly, 1986

What is the probability of having a Gang of Four combination after a well randomized shuffle? This probability is rather high: almost 30%! Here is why.

The rule to apply is the "hypergeometric law", which is a heavily used in surveys. We are dealing with a random drawing without putting items back.

Let's consider a bag that contains N balls where a number 'a' of them are red. We draw 'n' balls. The probability to get 'k' red balls is:

with: 

(n! meaning n x (n-1) x (n-2)... Example: 7!=7x6x5x4x3x2x1)

Applied to Gang of Four, this gives for a Gang of twos (N=64, a=6, k=4, n=16):

If you add up all probabilities (which is a good approximation, because the events are almost independent), you get:

Another interesting element is to compute the probability that the other players have one or more Gang of Four combinations when you have one in your hand

Number of Gang of Four for other players
0 1 2 3 4
knowing that your hand contains:
0 35.8% 39.7% 18.7% 5.0% 0.7%
1 31.3% 39.2% 21.8% 6.4% 1.1%
2 26.3% 37.5% 25.2% 8.8% 1.8%
3 9.1% 31.8% 31.8% 22.7% 4.6%