This works the same as @ttoe 's lottery but there will be a winner no matter what and there is a lower prize because i don't have as much mana.

place any bet and feel free to sell it imediatly after. You will be recorded as a unique trader. The total number of unique traders is n.

I will ask the random number bot (i forgot the name) to generate a number 1 to n. This number with be represented with x. The xth unique trader will receive 3n mana (total unique traders times 3 if this is unclear)

Just like @ttoe 's, this will resolve to 50%