Card chance based on count not random

[Ray]

There's unfortunately more to such a simple seemingly good idea. If it's based on count, what happens when you change the zone? If it's every 500 on the dot, you kill 499 on zone 1, then jump to the last planet for the next kill for the drop.

Penalize zone switching? Now we have angry members with pitchforks because you just reset or diminished the counter.