This is a simple darts game played with bitcoins. 

The rules are fairly simple, for each play you will be given a bitcoin address to send payment to 
and asked what address you would like any winnings sent back to. For each bet a payment hash is generated 
from a predetermined secret and the transaction id, and the last 4 digits (in hex) of that number will 
correspond to x and y coordinates on the dartboard shown below. 

You are given a hash of the secret before betting so you can verify after that the results are chosen fairly.
The amount you get paid back will depend on what section your dart lands.

http://is.gd/bitcoindarts