What is BitDouble?


BitDouble is a platform for unique games to gamble with Bitcoin. We are currently offering three games on our site and are planning on adding more in the future. You can either play versus the house or chat with other players.

You can read games rules on about page. All our games are provably fair — ensuring a fair play each and every time.

Do you have mirrors? What are BitDouble domain names?


Our primary domain name is bitdouble.io, that's English version of our website.

Official Russian mirror is bitcoindouble.io.

Official Turkish mirror is b2turkey.fun.

No others! Be careful!

What is a mBit ()?


All values on this website are denominated in mBit and one mBit equals 1/1000th of a Bitcoin. All values on this website are denominated in mBitcoin (mBTC) and one mBTC 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.

Do you have a faucet?

Yes, you can claim 0.005 per hour if your balance is zero.

New players can easily claim some tips in the chat rooms. Our moderators verify that you are a human and you can get bonuses after that. Please note that you are not allowed to jump between the chat rooms and claim tips everywhere! Do not annoy other players!

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 is 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?

Bitcoin deposit

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 chain.so or blockchair.com. If the deposit was sent correctly, then please contact support.

What are your VIP levels?

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 achievements.

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 roulette auto-betting feature?


We have created a very simple but powerful feature for our customers that allows them to easily «program» their roulette 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!

How can I play Bubble Game? What does the «Stop» button mean?

To start the game the player should place his bet and fix the altitude from 1 to 100, from which he’s planning to jump out automatically. The altitude is also a multiplier of your rate.

Then you should click the «Check in» button to get into the bubble. Now your bubble team is ready to fly to the moon! The bubble blasts off and starts to fly, at any moment you can click «Stop» (the button placed next to your rate) and jump out of the bubble earlier, this means that your gain will be multiplied by the altitude from which you jumped. The longer you stay in the game before pressing the Stop-button, the higher is the multiplication factor.

What is «One-click Signup»?

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 allowed. But you may contact support if there are legal or other important reasons to change your nickname.

How to change my avatar?


Go to the avatar page

Press button «Select image», choose picture, edit it and press «Save». Or you can create an avatar using our avatar generator.

What is Provably Fair?

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 game.

In short, for roulette 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 for Roulette and Bubble games?

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 17 yields the final roll in the range 0-16.

A JS implementation of the aforementioned process is included on Roulette Provable Fair and Bubble Provable Fair pages.