Why not add a function that allows a chance for more voodoo from something so useless? Here is the equation i came up with for voodoo to be gained from working in the port for labor:
t/2 + T = x% of 100
t is turns put into port
T is t/2 from last turn input if card wasnt obtained through the chance roll. Ex: if you put in 100 turns previously and didnt win a voodoo card, T is 50 to be reserved chances for winning a card next time you put in 100 turns or any amount of turns.
If you obtain a voodoo card, T is reset to 0.
More ex: put in 28 turns and T is 0, you have a 14% chance to get a voodoo card at that time from working labor. Then you put in 50 turns, your chances are now 39% to get a voodoo card.
Suggestions?