Forum Discussion

SamuraiUX's avatar
8 years ago

Probability and the Terrible Idea of Purchasing



The text for the Clan Mother pack reads: "Each pack guarantees at least 5 shards for Mother Talzin, and may drop up to 330 shards! Possible shard drops include: 5, 7, 10, 12, 15, 20, 25, 50, 80, 145, 230, 330."

I would've been happy with anything from 25 - 330 shards and disgusted with anything from 5 - 20 shards. I guessed that made my probability about 50/50 (6 of the outcomes were positive, 6 negative). My mistake was assuming the probability of all possible outcomes were equal.

My results across five id.i.ot.ic purchases were: 10, 10, 7, 5, 5.

Had the probabilities for all outcomes been equal, the probability of getting two tens in a row, for example, would've been 1/12 * 1/12 = 1/144. Same with getting those two fives. The probability of getting only outcomes in the "undesirable" half would be 1/2 to the 5th power, or 1/32. My conclusion is that while not explicitly stated, there is not an equal probability of all outcomes. Rather it is like pulling a slot machine: the 'better' outcomes are clearly less probable.

Pulling slot machines are addictive. I'm a d.um.my for doing it five times. That's my bad. EA is using "Dark UX" successfully, which is a moral grey area - but they're hardly the only ones doing it in mobile gaming.

I'm no whale, I shouldn't try. Don't do it, dude.