Originally Posted by
CJ54
The first and third are true and always have been (we've mentioned as much multiple times) but the second speculation is not. We do tweak things between events (we tweak just about every event, whether it is collect 10 or boss difficulty or drop rates or whatnot, to see what works best). And in collect-10 or collect 20/25 events (but not leaderboards), getting one of the special items decreases the chance of getting the next one. But it does not vary from account to account or take any other factors into consideration; everyone has the same percentage chances as everyone else who is at the same step of the event.
EDIT: Nor does it have to do with level or anything else like that. It's just a flat percentage based on how many of the tokens you already have.