BITCOINTALK.ORG · JUNE 20, 2013
STILL LIVE AT JUST-DICE.COM

Just-Dice

Before Uniswap. Before Aave. Before “DeFi” was a word — one developer on BitcoinTalk let strangers pool their Bitcoin and become the house. The first liquidity pool ran on a dice game. It's still running.

VERIFY THE AUTHOR
dooglus · BitcoinTalk
Chris Moore · Legendary · 11K posts · since 2011
VERIFY THE THREAD
Just-Dice.com : Play or Invest
242 pages · 455K reads · June 20, 2013
VERIFY THE ALGORITHM
github.com/dooglus/just-dice
Open-source verifier · HMAC-SHA512 · 12+ yrs
STILL LIVE
just-dice.com
Migrated to CLAM · same dooglus · 13 years on
// the algorithm

Provably Fair

The site couldn't cheat you. Not because dooglus said so — because the math wouldn't let it. Every roll was generated from a server seed committed before you played and a client seed you chose. The hash was published upfront. After the round, the seed was revealed. You could verify every roll yourself, forever.

provably-fair.js
// 1. server commits to a secret seed (you see only the hash)
server_seed = randomBytes(32)
commitment = SHA256(server_seed) // shown to you BEFORE you play
// 2. you pick a client seed
client_seed = "your-random-input"
// 3. combine seeds with bet number
message = client_seed + ":" + bet_number // e.g. "abc123:1"
hash = HMAC_SHA512(server_seed, message) // 128 hex chars
first5hex = hash.slice(0, 5)
decimal = parseInt(first5hex, 16) // 0 to 1,048,575
// if < 1,000,000 → roll = decimal / 10,000 (range 0.0000 – 99.9999)
// 4. after the round, server_seed is revealed
// you check SHA256(server_seed) == commitment
// 100% verifiable. 0% trust required.

This system became the template for every provably fair gambling site that followed. The code is still on GitHub — twelve years later — untouched, waiting for anyone to verify any roll from any session.

// the numbers

The Numbers

At its peak, Just-Dice held more Bitcoin than most exchanges — not in cold storage, but in a shared pool staked by anonymous forum members.

~50,000
BTC
PEAK BANKROLL
$4.5B+
USD TODAY
AT CURRENT PRICE
1%
HOUSE EDGE
PER BET
90%
TO INVESTORS
OF NET PROFIT
Value in 2013~$50,000,000
Max bet0.5% of bankroll · dynamic
Site commission10% of net profits
RandomnessHMAC-SHA512 · open source
BTC era (2013–2014)migrated to CLAM
Status (2026)still online · just-dice.com
DeFi Primitive Comparison
PRIMITIVEJUST-DICE · 2013UNISWAP · 2018
Deposit liquidity✓✓
Proportional shares✓✓
Earn from volume✓ house edge✓ swap fees
Withdraw anytime✓✓
Shared risk✓ bankroll P&L✓ IL
Open verification✓ HMAC-SHA512✓ contract
Permissionless✓✓
Built by one person✓—
// the announcement

The Announcement

On June 20, 2013, dooglus posted in BitcoinTalk's gambling board. He didn't pitch a startup. He didn't raise a round. He shipped a website and let the forum's anonymous degenerates stake the bankroll. The post that followed is the closest thing DeFi has to a genesis transaction.

Bitcoin Forum > Economy > Marketplace > Gambling
Just-Dice.com : Play or Invest : 1% House Edge : Banter++(Read 455,327 times)
dooglus
LEGENDARY
Activity: 2940
Posts: 11466
June 20, 2013, 03:14:02 AM#1

Check out the gambling site I made. It's a dice game, with the following features:

  • low 1% house edge
  • near-instant rolls
  • high limits — and the limits go up daily
  • provably fair (of course)
  • keyboard shortcuts for quicker, easier play

The really neat thing about it though is that you can also “be the house”, and invest any balance you're not using in the site's bankroll. Then when other players lose, you win.

Net profit is split between the house and the investors as follows: house gets 10%, investors get 90%.

Read the full original post ↗

// the exile

From BTC to CLAM to SOL

2013
BITCOIN
LIVE
50,000 BTC bankroll. Largest dice game in crypto. The original LP.
2014
CLAM
EXILED
Regulation forces migration. Same algorithm, ghost chain. Still running.
2026
SOLANA
REBORN
Same provably fair math. 400ms settlement. An actual market. Home.
// the game

The Game

01
CONNECT
Wallet + deposit $DICE
→
02
SET ODDS
Pick 1% – 98% chance
→
03
ROLL
HMAC-SHA512 · instant
RESULT
WIN
$DICE paid from house pool
LOSE
$DICE recycled to house pool
1% EDGE
Burned permanently from supply

Zero sell pressure from gameplay. Losses recycle. Burns shrink supply. Chart only sees buys.

The Flywheel

BUY $DICE
to play
VOLUME
generates fees
SOL JACKPOT
grows bigger
1% BURNED
supply shrinks
↘
↙
↖
↗
MORE PLAYERS
↑
ZERO
SELL PRESSURE
DEFLATIONARY
SUPPLY TREND
CREATOR FEES
JACKPOT SOURCE
ROLL 77.77
TRIGGER

Verify Everything

1
COMMIT
We generate a server seed and show you its SHA-256 hash before you bet.
↓
2
YOU SET
You choose your own client seed. This ensures we can't influence your rolls.
↓
3
ROLL
HMAC-SHA512(nonce:client:nonce, nonce:server:nonce)
5 hex → int < 1M → ÷10000 → result 0.00–99.99
↓
4
VERIFY
Rotate to reveal old server seed. Verify every roll at dooglus.github.io/just-dice ↗
SOURCE CODE
github.com/dooglus/just-dice
The original open-source verifier · by dooglus himself
VERIFY YOUR ROLLS
Just-Dice Verifier
Paste your seeds · confirm every number independently
// the token

$DICE on Solana

TOKEN$DICE · SOLANA · PUMP.FUN
CONTRACTTBA
UTILITYBET IN THE GAME · BURNED ON EVERY ROLL
SUPPLY MODELDEFLATIONARY · 1% BURN PER BET
GAMEPROVABLY FAIR DICE · LIVE NOW
JACKPOTSOL POOL · CREATOR FEES · HIT 77.77
SOURCEDOOGLUS · BITCOINTALK · 2013
PLAY NOW →
DeFi was invented on a forum in 2013.
Nobody noticed. It's still running.
Now it's on Solana.
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