PachinkoMaster is a free, physics-based random decision maker that runs entirely in your browser. No downloads, no sign-ups, no cost — just drop balls and let the physics decide.
Inspired by the classic Japanese pachinko machine, PachinkoMaster simulates real physics using Matter.js. Each ball you drop bounces unpredictably through a grid of pegs, landing in a random slot determined entirely by physical forces — not an algorithm quietly weighting the results. What you see is what you get.
Whether you need to settle a friendly debate, pick who buys the next round, assign chores fairly, choose tonight's dinner, or run a full knockout tournament with 32 players, PachinkoMaster makes the process transparent, visual, and genuinely fun to watch.
The board is built from a triangular grid of pegs. When a ball is dropped from the top, it collides with each peg and deflects either left or right based on the angle of impact and the ball's momentum at that point. After dozens of these micro-deflections, the ball settles into one of the prize slots at the bottom. Because the physics are simulated with real-world accuracy, tiny differences in drop position lead to dramatically different outcomes — making each drop genuinely unpredictable.
You can adjust the board to suit your needs: change the number of pegs, the ball size, the bounciness (restitution), and even the skin of each ball. Every setting is saved automatically in your browser so your setup is waiting for you next time.
Add your prizes or options Open the Prizes panel and type in whatever you want the ball to land on — team names, dinner choices, task names, anything. You can also assign point values to each slot and add images.
Choose single or multi-player For one person, just hit Drop Ball. For groups, open the Players panel and add each person with a custom colour. Each player's ball is colour-coded so you can track every drop at once.
Drop the balls Hit the big Drop button and watch the physics play out. Results are shown in real time as each ball lands.
Run an elimination tournament (optional) Enable Tournament Mode to run automatic elimination rounds. The bottom-scoring players are cut each round until one winner remains. Scores accumulate across rounds, so there are two ways to win: Last Standing and Points Champion.
Run a Knockout tournament (optional) Enable ⚡ Knockout Mode for a World Cup–style bracket tournament. Players qualify through a group stage, then face off head-to-head in seeded bracket matches until one champion is crowned.
Share or export Copy a shareable URL to send your exact board setup to someone else, or export the full leaderboard as a CSV file after a tournament.
Settle the age-old "what's for dinner?" debate, pick who does the washing up, or choose who goes first in a board game.
Assign tasks fairly, pick a sprint standup order, raffle a prize among colleagues, or run a competitive team tournament.
Pick which student answers a question, assign group members to projects, or run a whole-class quiz elimination game.
Run viewer giveaways, decide who picks the next game, or add a random-challenge twist to any group gaming session.
Run a draft order draw, decide home and away fixtures, or run a full World Cup–style knockout bracket with country flag ball skins for up to 200 players.
Live raffle draws, party game decisions, wedding table assignments, pub quiz tiebreakers — anything that needs a fair, fun result.
Knockout Mode turns PachinkoMaster into a fully seeded bracket tournament — think World Cup, March Madness, or any knock-out competition you want to run with up to 200 players.
The tournament runs in two stages:
Qualifying round Every player drops balls simultaneously. The top-scoring players advance to the knockout bracket — the rest are eliminated. You control how many qualifying balls each player gets and how big the bracket is.
Head-to-head bracket matches Seeded players face off one-on-one. Each player drops balls and the higher score advances while the other is knocked out. Matches continue round by round — Round of 64, 32, 16, Quarter-finals, Semi-finals, Final — until one champion remains.
The full bracket is visible at any time in the side panel, with a World Cup–style SVG bracket view showing every match, result, and the path to the final. At the end of the tournament you can export every qualifying score and bracket result as a CSV file.
You can configure the knockout tournament to suit any group size: choose the number of knockout rounds (1–7, which sets the bracket size from 2 to 128 players), set how many balls each player drops during qualifying, and set how many balls are dropped per head-to-head match. The qualifying stage automatically scales to fill the bracket from however many players you have.
Everything runs locally in your browser. No account required, no data sent to a server, completely free.
Yes. The outcome of each ball drop is determined by a real physics simulation, not a random number generator or weighted algorithm. Tiny variations in starting position cascade into wildly different paths through the pegs — it's chaotic in the mathematical sense.
There's no hard limit. You can add as many prize slots as fit on the board, and as many players as you like. For tournaments, we recommend between 4 and 64 players for the best experience.
Yes. PachinkoMaster is fully responsive and works on phones and tablets. On mobile, the ball size and peg density are automatically adjusted to suit the smaller screen. The app is best experienced in portrait mode.
Yes. All your prizes, players, and board settings are saved automatically in your browser's local storage. They'll be there when you come back — as long as you don't clear your site data.
All players drop balls simultaneously each round. The lowest-scoring players are eliminated (the cut-off is configurable). Scores accumulate across rounds. At the end, there are two winners: Last Standing (the player who was never eliminated) and Points Champion (the player with the most cumulative points). If the same player earns both, they get a Clean Sweep.
Knockout Mode is a World Cup–style bracket tournament. Instead of all players competing together each round, players qualify individually and then face off head-to-head in seeded bracket matches — winner advances, loser is out. It supports up to 200 players, with a qualifying round that narrows the field down to a power-of-two bracket (up to 128 players). The full bracket is displayed visually with all scores and results, and the complete tournament history can be exported as a CSV file when the champion is crowned.
Yes. Use the Share button to copy a URL that encodes your entire board configuration — prizes, players, settings and all. Anyone with the link can open the exact same board in their browser.
PachinkoMaster is completely free and requires no account, email address, or sign-up of any kind. Open the site and start playing immediately.
Got a feature idea, spotted a bug, or want to say hello? We'd love to hear from you: blipstermagic@gmail.com