CRAPS.

MULTIPLAYER CRAPS.

I knew I should have patented my provably fair card ordering algorithm.  The system used by this site is a direct ripoff of the "Cryptoproof" system I developed.

In this case, all rights would not mean exclusive use, as bitjack21.com has already been sold a copy of the code.  All rights means I give you code, I stop selling the code and relinquish any claims to ownership of the code, you are free to do with the code what you wish.

It is bitjack21.com's belief that they currently hold all rights to this code.  In the absence of any way to verify this I will have to give them the benefit of the doubt.

You may be interested in this:  https://bitcointalk.org/index.php?topic=38740.0

The site has been sold.  Thank you for your interest.

Buddy, the rule where dealer must hit a soft 17 favors the HOUSE.  It gives the house an extra 0.22% edge.  This would effective mean that on bitjack21.com, where the house edge is currently about 0.4%, it would go up to 0.66%...  This rule is BAD for the player and GOOD for the house.

http://bitjack21.com  - The site uses an honesty algorithm that is PROVABLY fair.  You dont have to take my word for it, you can PROVE it:
http://bitjack21.com/cryptoproof

I'm also selling the site (entire site, or just source code):

https://bitcointalk.org/index.php?topic=38740.0

Why you might ask?  I don't have the time to further develop it, and operating the site is somewhat of a legal gray area depending on where you live and choose to host it.

looking for a GREAT investment opportinity:  https://bitcointalk.org/index.php?topic=38740.0

The site has been sold, thank you for your interest.

[CLOSED]  The site has been sold, thank you for your interest.

[CLOSED] Site has been sold.

[CLOSED]

I'm running a promo that will start at 5 AM GMT 2011-08-23 (Midnight Eastern US Time) and run for 24 hours (until midnight Eastern US time 2011-08-24).  The prizes are as follows:

2 BTC - To the player who wins the most BTC.
3 BTC - To the player who loses the most BTC.
1 BTC - To the player who plays the most hands.

I will announce the winners here after the promo is over.  If this is well received I will make it a regular occurrence.

http://bitjack21.com

All good ideas!

Have you tried http://bitjack21.com ?

Update 8/13/2011:

In this pic you can see crypto-proof in action:

http://i52.tinypic.com/1zyj3ts.jpg

Technical details of crypto-proof available here:  http://bitjack21.com/cryptoproof

As of right now, the min bet is 0.02 BTC and the max bet is 0.75 BTC.  I'm willing to raise the max bet but my benefactors have informed me that I need to keep a 32:1 max:min bet ratio.  In other words the max bet will always be approximately 32 times the min bet (give or take a little bit).  So I could raise the max, but I'd have to raise the min as well.  Let me know if you guys would prefer a higher max bet, and as always, thanks for playing on bitjack21.com, the only bitcoin blackjack site on the internet that GUARANTEES that every hand you play is 100% honest, 100% random, and can PROVE it!

Roulette will likely be finished by the end of September.  It will be a multiplayer system with up to 4 players per table.

I considered offering insurance.  Then I decided it would add unneeded complexity to the code.  It is a mathematical fact that it is NEVER in your best interest to take insurance (over the long run). The only exception is if you are counting cards and the current count indicates that it is favorable to take insurance.  However, since you can't count cards in my game due to the decks being shuffled prior to every hand, then it is NEVER in your best interest to take insurance.  Now some people have told me I should offer insurance for this very reason (because it works in favor of the house).  If this is something people want then I will consider it as a future enhancement.

As for surrender, no, I will not be offering it.  The house edge with the current rules is very very thin (about 0.35%).  Blackjack also has a very high variance.  Because of these things, there are many days when I end up losing significant amounts of bitcoins, and that is why I can not add surrender.

Hand history and win loss ledger will definitely be coming soon as enhancements.

Also, as of now, I have my "crypto-proof" system turned ON.  This system *proves* that every hand you play on http://bitjack21.com is honest.  It proves that:

1.)  The order of the cards was 100% completely random.
2.)  The order of the cards was determined just before the hand started and did not change during the hand.

I have posted an informative page on the site about how the crypto-proof system works, and how you can use it to verify that any given hand was honest:
http://bitjack21.com/cryptoproof

Thanks for playing!
-Mr. Sizlak

OK, I have found a way to COMPLETELY, 100%, beyond any reasonable doubt, *PROVE* that my game is 100% honest.

It only seems fitting that cryptography, which is the basis for our trust in the bitcoin system, will now be used as the basis for trust in my bitcoin blackjack game.

Here's how it will work:

1.) Embedded in the client side javascript code of the game will be a random number generator.  It will generate a random number prior to each hand (call this number R2).  The user will have the option to either use the number generated by their web browser, or modify it as they see fit.

2.)  When the user clicks on "DEAL", their random number will be sent to the server.  The server will generate 2 of its own random numbers, call them R1 and RX.

3.) The server computes SHA256(R1 + RX), and sends this back to the user, this is displayed in the user's browser at the start of each hand.

4.) The server generates a very long string of random bits by calling
SHA256(R1 + R2 + 0)
SHA256(R1 + R2 + 1)
SHA256(R1 + R2 + 2)
SHA256(R1 + R2 + 3)
etc...

This string of random bits essentially *is* the deck order.  In other words, you can directly determine the order of the cards in the deck directly using this (I will be posting the function).

5.) AFTER the hand is over, the server displays to the user the actual values of R1 and RX.

This will allow the user to mathematically prove/verify that:
1.) The order of the cards was COMPLETELY RANDOM.
2.) The order of the cards was predetermined prior to the hand starting.
3.) The order of the cards did not change during the hand.

-Mr. Sizlak

Max bet is now 0.5 BTC (it will continue to rise as we get more players).

People who have played on my site, do you have any suggestions?