Fair rounds
In the nano133 arcade, your score comes from what you do and, in most games, from the round's random parts. Those parts are fixed before you start, made so that nobody can pick them (not even us), and shown to you after the round, so you can check them yourself.
In short
- Before you start, the round shows a commit: a code that locks in a secret we picked for this round.
- When you press Start, your browser adds a random number of its own, the nonce. The secret and the nonce together make the round's seed. We add nothing after we see your nonce.
- After the round, the score card shows the secret. Its Fairness panel checks, in your browser, that the secret matches the commit your browser showed, that the seed is the one the secret and your own nonce make, and it plays your round again from your inputs to show the same score.
- Every player's seed is made the same way. Nobody can choose an easier or a harder one: not you, not other players, not us.
Skill and chance
A round's random parts set the scene: where things start, which way they move, what a computer player does. Within that scene, your moves decide the score.
Some scenes are easier than others, and in some games the scene changes the highest score you can reach. In Block Beat, the patterns have more or fewer notes. In Alley Roller, the 100 pockets are lit on more or fewer balls. On a pinball table, the lit skill-shot lane can be easy or hard to hit. The scene can also change how long a round lasts (in Reaction, how long each wait is), and a paid round earns tickets for each minute it is played, more for a better score. So two rounds played the same way can score differently and earn different tickets, and most paid rounds are a mix of skill and chance.
When you finish a round, our server works out the points itself from the round's seed and your inputs: it plays the whole round again (in Reaction, it checks each of your times). The page's own score is never trusted. Tickets come from that score and the round's play time, which our server also measures itself, by the same rule for every player. A Nano Island round gives no tickets: its score goes only on the island board.
Prizes are cosmetic: they change how things look and give no advantage in any game. Prizes, tickets and tokens have no cash value. See the Terms.
What is random in each game
| Game | The seed decides | Never random |
|---|---|---|
| Reaction | How long each wait is (so how long the round lasts, which changes its play-time tickets), and which later rounds have a fake-out flash. | The number of rounds and the shortest and longest wait. |
| Snake | Where each block and gold block appears, and where each level's walls go. | Movement and speed. A wall never lands just in front of you. |
| Fair Claw | Which toys are in the pit and how many fit (up to 20 since 2026-10-14; a round that started on the older pit of up to 16 keeps it), where, which way they face, and each level's refill. | The grip. A toy holds or slips only by how close the claw closes to its center of weight. The balls: each grab that takes no prize is 1 ball, so a full round has 3 for every player. The seed does not decide them. |
| Spam Defense | Each wave's spam and payments: where they start, what they aim at, how fast, which ones split. | How many come, how fast each wave gets, and your shots. |
| Maze Runner | Each level's maze, and which way the bots run while they flee. | How the bots chase you, their speeds and how long they roll back. |
| Pinball (all tables) | On every table, the side a stuck-ball kick goes. On Block Lattice, Feeless Express, Proof of Work and Genesis, the lit skill-shot lane (on some tables, some lanes are much harder to hit than others). On Block Lattice, how hard and which way the saucer kicks the ball out. | All other ball and flipper physics and all scoring. Rug City lights its skill-shot lane by ball number. |
| Crossing | The world, row by row: lanes, cars, logs, trains, coins. | Your hops, and how each zone gets harder. |
| Rock Blaster | Where each wave starts, the rocks' speed and direction, the saucers' timing, path and aim. | Your ship's physics. Small saucers aim at you more closely each wave. |
| Air Hockey | Who serves first, and the computer player's choices to strike, its aim and its error. | Puck and mallet physics, and the computer player's reaction time at each level. |
| Block Party | Daily Run only: which level, mirrored or not, and how many of each job. | A normal run plays the same levels in the same order. |
| Swish | The computer shooter's waits, and the power and aim errors of its shots. | Ball flight and rim physics, and how the hoops move at each level. |
| Robo Rumble | The computer boxer's guards, sways and punch timing. | Whether a hit lands, reach, timing and stamina. |
| Alley Roller | Which target is lit for double points (one of the four inner rings, or the 100 pockets), and where the two 100 pockets slide, each ball. A lit 100 pocket scores 200, so the highest score you can reach changes from round to round. | The roll is exact physics. The hand's wobble comes from your own input. A ball that lands in the ring around a 100 pocket, or rolls into it slower than 3 m/s, and misses the pocket scores 30, or 60 when the 30 is lit. |
| Block Beat | Which hand-made patterns each bar uses, and how their lanes are flipped or turned. The patterns have different numbers of notes, so the highest score you can reach changes from round to round. | The songs' form, tempo and chords. The Daily song is the same for everyone. |
| Lattice Darts | The path of the hand's slow sway for each dart: where it starts and which way it drifts. | How big the sway is, the board, the power from how long you hold, and how far a dart drops or rises. Where you aim, when you let go and how still your thumb is are your own input. |
| Pairs | Which cards are on each of the 3 boards, where each card lies, and which cards change places, in your view, before you play (none on the first board, then 1 change, then 2). Pairs has no Daily Run: a Daily Run's seed is public, and in Pairs the seed is the boards. | How long each look lasts, how long each board lasts, what a pair scores (100 from the look, 50 when one of its cards was turned before), the bonuses (a row of pairs, a board with no wrong turn, and on a finished board each full second under the board's par) and what a wrong turn takes away (30, then 60). A board never goes under 0. The highest score is the same in each round. |
| Tower Stack | For each floor: the side the block comes from, its speed (0.9 to 1.15 times the floor's own speed), and where the FAST and PULSE blocks fall in each group of 4 floors (in the City and in Space). From the Clouds, the wind: its side and how strong it is (4% to 12% of the first block's width), the same for 5 floors. The block's speed shows as it slides, and the wind's side shows on the screen. | Each floor's own speed (3.5% faster each floor, up to a ceiling), how many FAST and PULSE blocks there are, the perfect distance, the cut, where the block turns back, the 6 passes before it drops by itself, and the score. A perfect drop is possible on every pass, so the highest score is the same in each round. |
| Whack-a-Spam | Which 8 of the round's 22 pops are real payments (the first pop is always spam), and the hole each pop comes up in (never a hole where a pop is still up). On a Daily Run the seed is the day's public seed, the same for everyone. | The round's 20 seconds, the 22 pops, when each one comes up and how long it stays up (from about 1.1 s at the start to about 0.5 s at the end), and the score: a spam tap scores 100, plus up to 100 for an early tap; a tap on a payment takes away 150; a payment you leave alone scores 40. The highest score is the same in each round. |
| Puzzles | Where the pieces start, how they are turned, and which are face down; and where Gather heaps the loose pieces (from the seed and the moment you press Gather). | The cut: every player solves the same puzzle at each size. |
| Coin Bees (Nano Island) | Which 7 of the floor's vote spots hold the votes, where each guard bot starts on its path and its timing, where FUME starts, where WOOF starts, and which end each HEFT starts from. | The floor and the Heat's changes to it, the bots' paths and how they see and hear, the clock, your moves and the score rules. |
| Banano (Nano Island) | The path: which chunks fill each zone (each zone stays within the same range of difficulty), which are mirrored (a mirrored gust blows the other way), which side of each fork drops, how the spam bots drift from Pace 2, where the powers are and which ones, and where the rare XRB is. | The first and last chunks, the landmark chunks, each island's length (1,200 m on Genesis Grove, up to 2,000 m at Genesis Summit), the gust rows, the vote tiles, the quorum gates and the votes each gate needs, each Pace's speed and edge, the monkey's moves and the score rules. |
| Ananos (Nano Island) | The waves (24 on most dojos, 16 on Katana Trial and at the King's Fort): their kinds where the dojo does not fix them, which produce comes in each (at the Smoothie Stand, which items are on the ticket and which are decoys, so a wave can have no order to finish and the highest score changes from round to round), when and where each item is tossed and how high; the extra items of INSTANT; how fast the King's six pineapples burst out; and each item's spin. | Each belt's speed, share of fee coins, target and gap between waves, each dojo's wave script, its tickets and its share of decoys, the King's armour on each belt, the 4 play fields, the blade's rules (its width, the wider touch blade, and its top speed: a stroke faster than 4 field units in 8 ms does not cut), the points, the combo, the 3 lives and the stars. |
| Quorum Kitchen (Nano Island) | The Day: each order's dough, wishes and "no", the oven's quirk, the Election's twist, each judge's secret like (and the weights on a Big Judge day), on Fork Night which two judges form side B, the order in which each order's cards are dealt, and the Market's cards and tools. | Every card's values, the Dough Map and its zones, each Day's panel of judges, the judges' likes, dislikes and weights, the targets, each apron's Election target, the score rules and the Crumbs. In a paid Day our server holds the seed, so the page never knows the hidden parts before you play. |
None of the games uses the clock or a random number outside its seed. The same seed and the same inputs always give the same round.
Kinds of rounds
- Paid and token rounds, and free challenge rounds when you are signed in: committed as above.
- Daily Run: no commit. Its seed is public and the same for every player that day (made from the game and the date), so everyone plays the same round.
- Ananos Daily Run: a 2¢ entry plays Beach Dojo on White belt, with the same square field, seed and rules for everyone that UTC day. Free practice plays the same run. Only paid entries reach its daily board, and only your best score counts. Equal scores share a rank. Entries close at 00:00 UTC; rounds already started have up to 15 more minutes to finish before the standings are final. No tickets or story progress.
- Practice rounds (not signed in), Nano Island free play, the free stages of Tower Stack and Block Party, the free boards of Pairs, and the clubs of the Lattice Darts Ledger Tour: not recorded and not checked.
- Duels in the 3D room: free. Both players get the same seed from the room server, and both play the same table. The seed decides who serves first in Air Hockey and the hand's sway for each dart in Lattice Darts; Robo Rumble and Swish duels use none. Duels pay no tickets or prizes. Each match is played again by our site to decide the result.
- Rounds from before these checks show "Started before fairness checks". They were still played again from their seed and inputs to score.
Check a round yourself
- Before you start, note the commit on the screen ("commit 3f9c1a…e2b7").
- After the round, open Fairness on the score card. It shows the secret, your nonce and the seed, checks them, and has Replay this round.
- Or paste the round's id here: this page reads the proof our server kept and checks it in your browser. It shows the round's commit, so compare it with the one you noted.
Technical details
For readers who want to check the math (version 1):
secret: 32 random bytes (written as 64 lowercase hex characters), picked by the server when the round's session is made, kept on the server until the round is over.commit = SHA-256("nano133-fair|v1|" + roundId + "|" + secret), shown before the round starts (hex).nonce: 16 random bytes made by your browser after it shows the commit, sent with Start. A round does not start without one. Your browser keeps it, and the commit it showed, to check the round with.seed= the first 4 bytes, big-endian, ofHMAC-SHA256(key = the secret's 32 raw bytes, "nano133-fair|v1|" + roundId + "|" + nonce + "|NONE")(a seed of 0 becomes 1). A Reaction round makes its waits from the seed; a puzzle makes its scatter from it.- Rounds started before this change went live (from 4 October 2026) also mixed in the hash of a Nano block from our node in place of
NONE. Their proofs show that block, and the checks use it. We stopped, because we chose that block after we saw your nonce. - Because the secret is fixed (and committed) before your nonce exists, and nothing we choose later goes in, we cannot steer the seed. Because you never see the secret before the round is over, you cannot either.
- The proof of any round:
GET /api/arcade?fair=<roundId>. The secret appears only once the round is over.
Questions or something that doesn't add up? Press Feedback: reports are welcome, and real bugs earn a reward (rules).