The whole game is basically one giant random number generator, so there was a lot to gamble on.

E.g., two players put one million gold pieces in their inventory, equip no equipment (so no attack bonuses), every hit on each other is now an RNG roll with identical odds for each player. Battle to the death and voila.

That one's quite basic but there were more elaborate games such as flower poker. The game had a flower seeds item which when planted would spawn a flower on the floor. The flower would be of a random color (e.g. red, blue, white, ...). People would bet on which color flower would pop up, or plant plant five flowers sequentially and try and get something akin to a poker hand (e.g. three of a kind, full house).

Quite silly, in retrospect, as I'm typing this out.