I was wondering this as well. Was thinking maybe you had to get 5 of a kind against him, but I couldn't do it after 30 minutes. I did end up making a bunch of Orens though, so it wasn't a complete waste. Maybe it has something to do with an item you need
or perhaps it's part of a quest...
Glad I found this post before I wasted more than the 30 min I already did on him. Some good came of it though - in my 3rd game against him, I got the Poker! achievement! Glad that one is behind me. :-) Thanks all for the info here so I can move on.
I got five of a kind against him and still nothing. After reading other comments it's clear what has taken place. There's no point in linking PC games to an Xbox audience, so evidently they removed the prize from our port.
Also, I had forgotten these forums existed until I went googling for answers just now. HAI FORUMS