Japanese versions (and some useful tools) are here.
---- [Basic rules] ----
You can select some cards, consisting a prime number, and play them.
(You can select "4", and "3", and "PLAY" as the prime number 43.)
If CPU played prime number, you must play a bigger number using the same number of cards.
(If CPU played "4,3", you can play "4,7", "8,9", or "12,7" etc. You can't play "4,1" or "5,2,3".)
To win the game, use your all cards.
---- [Draw] ----
If you want, you may draw one card during your turn.
---- [Penalty] ----
If your number is not prime, you have additional cards as many as you tried to play, and your turn is over.
(You may do it on purpose if you do want many cards.)
---- [Factorization] ----
Using prime factorization, you can play composite number.
For example, click in order "2","for factor","3","for factor", "6", "PLAY".
Then you can discard those 3 cards and play the composite number "6" without penalty.
If the factorization is not correct, you receive penalty.
---- [Factorization (using exponent)] ----
Click in order "2","for factor","3","for factor(exponent)", "8", "PLAY".
Then you can discard those 3 cards and play the composite number "8" without penalty.
---- [Joker] ----
The card "★" is joker. You can use it as any integer from 0 to 13.
You can also use it as "INFINITY", the strongest card, if you use this card alone.
---- [Special rules] ----
57("Grothen-Cut") and 1729("Ramanujan Revolution") have special effects.
They are not prime, but you can play those without factorization. Then,
57: you have your turn again.
1729: reverse the order. (After this, players must play smaller number than the previous one.)
---- [Contact] ----
Twitter: nishimura@icqk3
Released: 9 Jan 2019 / Last update: 29 May, 2021
(PrimeQK was named after the prime number 1213, the biggest prime number with 2 cards.)

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