52!

How to play

Two modes, one deck each, no purchases and nothing to learn

52! is a free card game about a number so large it has no useful comparison left. Two decks are shuffled and turned over side by side; you are watching to see how far the coincidence runs. There is nothing to buy, no currency, no levels and no tutorial — everything you need is on this page, and it takes a minute to read.

The basic move

There are two decks on the table, a left one and a right one, each shuffled independently. Tap the table (or press Enter or Space) and one card is turned over from each. Either they are the same card, or they are not. That is the whole mechanic.

What changes between the two modes is what happens next.

Mode 1 — “Until you miss”

The default mode, and the one the leaderboards are built around.

Matching the very first pair is a 1-in-52 event, so most rounds end at zero. That is normal and it is meant to. Getting two in a row is already a 1-in-2 652 event — rarer than being dealt four of a kind in poker. Three is 1 in 132 600.

What is a good score? Anything above zero is worth noticing. A run of 2 puts you ahead of the great majority of rounds ever played here. A run of 4 or more is genuinely rare. The world record on the leaderboard has been sitting in the low single digits, which tells you everything about how steep this gets.

Mode 2 — “All 52 pairs”

Same two decks, one rule changed: you do not stop at a miss. All 52 pairs are turned over and you count how many matched anywhere along the way, in a row or not.

This mode feels completely different, and the maths says it should. The expected number of matches is exactly 1, and you get at least one match about 63% of the time — so most rounds end with something to show. Five matches is a 1-in-273 round. Ten is 1 in 9 million.

Both modes share the same impossible ceiling: all 52 is a 1 in 8 × 1067 event either way. The maths page works through why two modes that feel so different end up at the same wall.

Switching modes

The toggle sits just above the table — Until you miss on the left, All 52 pairs on the right. Your best score in each mode is kept separately, and both have their own leaderboard. Switching mid-session is fine; nothing is lost.

Reading the screen

What you see What it means
Total plays Every round played on this site by everyone, ever.
Winners Players who have matched all 52. It reads zero, and it is going to stay that way — see the maths.
World best The longest run anyone has managed, with a “×N” if several people are tied there.
Most nailed The single card that has been guessed correctly more often than any other.
Your attempts / your best Your own totals, kept on the server so they follow you between devices once you sign in.
The odds ruler A scale showing how rare each score is, next to things people have a feel for — a coin flip, a hole-in-one, the Euromillions jackpot. You can switch it between the two modes independently of which one you are playing.
The period dropdown Today / this week / this month / all time. It filters everything on screen — the global numbers, your own, and the rankings.

Auto play

The Auto play ×100 button runs a hundred rounds for you, much faster than tapping. Tap the table at any point to stop it; you get a summary of what happened. It counts for your statistics exactly like rounds you played by hand — the shuffle and the result come from the server either way.

Day streaks and daily rewards

Play at least one round on a given day and your day streak goes up. Miss a day and it starts again at 1. Each new day awards free auto plays — one a day at first, more as the streak grows, with bigger jumps at a full week and a full month. Days roll over at midnight UTC (the server’s clock, the same for every player, which is the only way a streak can be counted fairly).

Your balance shows as a small number on the auto play button. When it runs out the button shows a video icon instead.

Accounts, names and rankings

An anonymous account is created for you automatically — you can play immediately, with no sign-up. You can set a public name, and you can link a Google account so your record follows you to another device. Tap any name in the rankings to see that player’s best score in each mode and their day streak.

Is any of it skill?

No, and the game does not pretend otherwise. Both decks are shuffled by the server before your round starts, and nothing you do changes what is in them. There is no strategy, no pattern to spot and no card that is “due”. What you control is how many rounds you play — and that is exactly what the leaderboards measure.

If you would like to check that the shuffle really is fixed before you play rather than picked afterwards, you can: see how the fair shuffle works.