What is BitDouble?

BitDouble is a brand new way to gamble with Bitcoin. We are NOT a dice site – instead players deposit Bitcoin and bet those coins on a roulette inspired game:

The five options that players can bet on are:

Red 1-7 to DOUBLE your Bitcoin
Black 8-14 to DOUBLE your Bitcoin
Even Even to DOUBLE your Bitcoin
Odd Odd to DOUBLE your Bitcoin
Green 0 for FOURTEEN times your Bitcoin

It doesn't matter how big your Wallet is, or how much you bet, your odds are always the same.

Bets occur in real time, across the entire site, meaning you bet, win, and lose along with other players.

All rolls are generated using a provably fair system – ensuring a fair roll each and every time.

What is a mBit ()?
All values on this website are denominated in mBit and one mBit equals 1/1000th of a Bitcoin. This was done because entering bets in Bitcoin would be tiresome with all the decimal places to keep track of.
How many confirmations do the deposits need?
Depending on the size of the deposit we require 1 or 2 confirmations. Our system needs to wait for blockchain confirmations before the Bitcoin are added to your account balance. Usually a confirmation takes about 10 minutes, but this is an average value and can be much faster or slower. Go to your Deposit page to see how many confirmations are needed and how many you already have. If the deposit has many confirmations and was still not added to your account, please contact support.
I made a Bitcoin deposit and it's not showing on the deposit history. Where is it?
If you made a deposit and it isn't showing up on the Deposit page after a few minutes, try checking if you can find the transaction using a blockexplorer like blockchain.info If the deposit was sent correctly, then please contact support.
What limits do you have? How much can I win?

The maximum bet you can place is 500 (0.5 ) and if you place a bet on green you can win 500*14 = 7000 (7 ). These limits will be raised gradually in the future.

The minimum bet is 0.001 .

Do you have a faucet?

Yes, you can claim 0.025 per hour if your balance is zero.

What are your VIP levels?

We are awarding our high volume players with a certain badge of honor depending on his VIP level. Their avatar will receive a bronze, silver, gold or diamond outline with beautiful design to showcase their achivements.

Also you get a significant bonus for achieving each level.

There are ten VIP levels and you can reach then with the following wager requirements:

Level Wager Requirement Bonus
VIP 1 VIP Level 1 Bronze > 100.0 1.0
VIP 2 VIP Level 2 Bronze > 500.0 5.0
VIP 3 VIP Level 3 Bronze > 1500.0 15.0
VIP 4 VIP Level 4 Bronze > 5.0 50.0
VIP 5 VIP Level 5 Silver > 15.0 150.0
VIP 6 VIP Level 6 Silver > 50.0 0.5
VIP 7 VIP Level 7 Gold > 150.0 1.5
VIP 8 VIP Level 8 Gold > 500.0 5.0
VIP 9 VIP Level 9 Diamond > 1500.0 15.0
VIP 10 VIP Level 10 Diamond > 5000.0 50.0

As you can see the higher VIP levels are very hard to obtain and only the biggest whales will be able to reach it! A true badge of honor.

What is the auto-betting feature?
We have created a very simple but powerful feature for our customers that allows them to easily «program» their betting strategies and then let the bot place the bets for them. For example if you want to double the bet each time you lose and return to the basebet once you win (martingale) then it only takes you few clicks to program this!
What is «One-click Signup»?
With this feature you can create an account with one click. This means it will give you a random username and password that you can find in your Settings. If you don't save these login data and delete your cookies/close your private browsing page, your account will be lost and can't be restored by our support team!
Can I change the nickname if I don't like it anymore?
This is not yet possible, but in the future you will be able to do that.
What is Provably Fair?

Provably fair is a way of generating random numbers using cryptography such that the results can be verified by a third party. This means the operators cannot manipulate the outcome of any roll. In short, we use the results of the Bitcoin blockchain to seed our RNG (random number generator) – for a detailed explanation see below.

Provable fairness has been verified by TheBitcoinStrip.

How does it work?

Each roll is computed using the SHA-256 hash of 3 distinct inputs.

First, is the server seed. This is a precomputed value generated by BitDouble some time in the past. Seeds are generated in a chain such that today's seed is the hash of tomorrow's seed. Since there is no way to reverse SHA-256 we can prove each seed was generated in advance by working backwards from a precomputed chain.

seed 0 => seed 1 => seed 2 => seed 3

Next, the server seed is salted (scrambled) with the last 16 bytes of the hash of the last Bitcoin block with height equal to the largest height divisible by 100, which has at least 7 confirmations.

Finally, each roll is salted with the unique round id ensuring a different hash each roll.

The round's hash is generated using SHA256("serverseed-salt-roundid"). Taking the first 16 hex digits of the resulting hash and converting to decimal yields an integer from 0-2^64. Taking modulo 15 yields the final roll in the range 0-14.

A JS implementation of the aforementioned process is included on Provable Fair page.

How do I verify a roll?

On our Provable Fair page we added a script that you can use to check rolls.
You can also download JS script and check it.

How does the affiliate system work?

The affiliate system lets anyone earn credits by referring new players to the site. Visit the affiliate dashboard to find your unique referral code. Share with friends, in forum signatures, or on social media. Please don't spam your link, otherwise we might have to close your account!

When new players use your referral code they'll get 0.025 FREE after e-mail confirmation. And you'll earn credits every time your referrals place a bet – regardless if they win or lose.

What is affiliate level?

Your affiliate level determines how much (%) you'll earn from each referral's bet. Your affiliate level is determined by the amount of volume your players made:

Volume Affiliate Levels:

  • Referral Level 10-50 — Bronze (1 per 300 bet)
  • Referral Level 250-500 — Silver (1 per 200 bet)
  • Referral Level 3500+ — Gold (1 per 100 bet)

You can track your visitor statistics from the dashboard. Affiliate payments are sent once each day automatically to your account balance.