Quote from: voidmain on September 30, 2014, 10:52:20 AM

Introducing a JackpotCoin Slot Machine

It's not very easy to make provably fair online slot machine.
How can you believe that server side generated random number is true random?
Or, how can a client generate random number accepted by server eliminating a tiny possibility of hacking attempt?

I've come up with an idea.
1. No one can predict upcoming block hash.
2. Roll the slot. Server generates 4 random numbers between 0~15.
3. Wait for the next upcoming block hash.
4. Pick the last 4 digits of the block hash, which are supposed to be evenly distributed within the range of [0,1,2,3,4,5,6,7,8,9,a,b,c,d,e,f].
5. Compare how many of them are matching.
6. Luckily JackpotCoin block generation is average 20 seconds. Don't have to wait for too long.

Loock at the screenshot below.

Interested? Come and try. Coins On Table have added a new game, JackpotCoin Slot Machine!
https://cryptfun.com/cot/

Pay table
The full award starts from 2,000,000 JPC.
When any player inserts a coin, it will be accumulated into the machine.
4 matches will take 100% of accumulated coins in the machine you are playing.
3 matches will take 5% of accumulated coins in the machine you are playing.
2 matches will take 0.5% of accumulated coins in the machine you are playing.
1 matches will take 0.1% of accumulated coins in the machine you are playing.
Whenever the accumulated coins fall below 2,000,000 JPC, the system will refill it to 2,000,000 JPC.
10% game fee.

For some, this could be felt a bit too slow.
Blue machines are fast, more intuitive and fair, but it's not provable.

You can also enjoy player-vs-player rock paper scissors game.
https://cryptfun.com/cot/

This is really cool, the amount of thought and effort really shows. I'll give it a spin next time I have a chance to transfer some coins